light Dictionary Terms
averted visionIn astronomy, the method of deliberately viewing objects with peripheral vision to take advantage of the eye's greater...
photochromismThe reversible change in the absorption spectrum of certain compounds upon irradiation with a given wavelength of light.
Savart polariscope1. A polariscope consisting of a Savart plate and a tourmaline plate analyzer, and used to produce parallel color fringes by...
effect filterA color filter, generally used in photography, to emphasize certain color tones and to modify others in a picture for a more...
petrographic specimen preparationThe grinding and polishing of rock samples, to a thickness of less than 0.05 mm, for study with petrographic microscopes....
broadband dielectric mirrorsBroadband dielectric mirrors, also known as broadband mirrors, are optical coatings designed to efficiently reflect or...
fiber optic cable assemblyA fiber optic cable assembly refers to a complete unit consisting of optical fibers, connectors, protective jackets, and...
light fidelityLiFi, short for light fidelity, is a wireless communication technology that utilizes visible light or infrared light to...
additive color mixingProcess in which two or more lights are combined by superposition.
dark boxA lightproof box used for storing photosensitive materials.
focal lengthThe focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or...
black lightRadiation from the invisible (usually ultraviolet) region of the spectrum.
surface-emitting laser diodeA semiconductor laser diode that emits light perpendicular to the active region. The output radiation is taken through the...
elliptically polarized lightA light beam whose electric vectors are broken into two elements of unlike amplitudes that are perpendicular to each other...
short-arc lampA compact high-pressure light source in which an electrical discharge between electrodes spaced no more than 12 mm apart...
optical headIn compact disc and CD-ROM technology, the portion of the drive that projects the laser light onto the surface of the media...
dioptricsThe branch of optics that deals with the study of the refraction of light, particularly by the transmitting medium of the...
copper oxide photocellAn early type of nonvacuum photocell consisting of a layer of copper oxide on a metallic substrate, with a thin transparent...
reference beamIn holography, the beam of light that is directed from the beamsplitter to the recording medium, where it interferes with...
linear opticsLinear optics refers to the study and manipulation of light in a linear and deterministic manner, where the response of...
equivalency widthCalculation of the amount of energy extracted from a light beam regardless of its wide range resolution.
axiconAn optical device that produces a line image lying along the axis from a point source of light; therefore, it has no...
object beamIn holography, the wave of light that illuminates the object to be recorded, which diffracts it to the recording medium,...
fluorophoreA fluorophore is a molecule or a portion of a molecule that has the ability to emit light upon excitation by an external...
Bragg gratingA filter that separates light into many colors via Bragg's law. Generally refers to a fiber Bragg grating used in optical...
self-luminous light sourceAny material that derives its energy from chemically or electrically induced reactions; isotope or radium excitation is used...
single-photon avalanche diodeA single-photon avalanche diode (SPAD) is a specialized type of photodetector designed to detect extremely weak optical...
rotating wedgeA circular optical wedge (prism of small refracting angle) mounted to be rotated in the path of light rays to divert the...
flying spot scannerA device used to scan, with a small, intensely bright spot, portions of a picture surface and to transform the original...
nitrogen vacancyA nitrogen vacancy (NV) refers to a specific type of defect or impurity in a crystal lattice where a nitrogen atom replaces...
sheet polarizerA sheet of plastic material containing microscopic crystals of herapathite or some other similar substance that transmits...
diffraction efficiencyDiffraction efficiency is a measure of how effectively a diffractive optical element (DOE) or diffraction grating directs...
Nd:YAG laserNd:YAG laser refers to a solid-state laser that utilizes neodymium-doped yttrium aluminum garnet (Nd:Y3Al5O12) as the gain...
opticsOptics is the branch of physics that studies the behavior and properties of light, including its interactions with matter...
photon sieveA photon sieve is an optical device used in the field of optics and imaging. It's designed to focus and shape light,...
flux rise timeTime elapsed during the radiant output change from 10 to 90 percent of maximum in a light-emitting diode or laser. Usually...
fusion1. The combination of the effects of two or more stimuli in any given sense to form a single sensation. With respect to...
cinesextantAn optical instrument used to track and image a test vehicle (target) throughout its flight. The cinesextant frequently...
Doppler-Fizeau principleThe principle stating that the displacement of spectrum lines is determined by the distance between, and relative velocity...
airglowDiffuse light emitted by the atmosphere due to the excitation of particles of atmospheric gas. These excited particles...
compensating filterA filter used in photography to change the spectral composition of light entering a camera, or to adjust color balance...
spherical aberrationSpherical aberration is an optical aberration that occurs when light rays passing through a lens or curved optical surface...
interferometryThe study and utilization of interference phenomena, based on the wave properties of light.
self-electro-optic effect deviceAn optically bistable device used for photonic switching, constructed of a multiple quantum well biased by an external...
globarA light source made up of silicon carbide or carborundum. It is resistant to the negative temperature coefficient and...
continuous waveContinuous wave (CW) refers to a type of signal or transmission where the signal is constant and does not vary with time. In...
fery prismA prism with curved faces that collimates, reflects and refracts incident light. Often used in the production of...
card readerA system that generally uses a photodetector to decode punched cards for information, or for input to a computer, by sensing...
injection luminescent diodeA semiconductor diode operating in either a coherent or incoherent mode that is used as a near-infrared or visible source in...
confocal scanning microscopeA microscope design that involves apertures inserted in conjugate plane positions inside the microscope, with one aperture...
turbidityTurbidity is a measure of the cloudiness or haziness of a fluid caused by the presence of suspended particles. These...
flat-field frameA frame taken with a CCD camera of a surface that is evenly illuminated by diffuse light. This frame shows irregularities in...
Maddox rodLenslike composition of stacked glass cylinders through which a spot of light appears as a streak perpendicular to the...
light filterA homogeneous optical medium or coating that transmits only in particular regions of the spectrum. It is used to change or...
electronically controlled couplingThe use of an electric field or signal to couple a lightwave from one dielectric waveguide into another dielectric waveguide.
convergent beam sensing modeA type of photoelectric proximity mode sensing incorporating a lens system to focus the light from the emitter in a small,...
digital cameraA digital camera is a device that captures and records still images or video in digital format. Unlike traditional film...
bistatic reflectivityCharacteristic of a reflector that reflects light along a different line or lines than that of the incident ray.
Raman absorptionThe absorption of part of the photon energy by a molecule through which there is a slight energy change and the energy...
venetian-blind effectShort-distance scattering of light in holography caused by random index inhomogeneities and the developing index that...
cementing surfaceThe surface of an element of a compound lens that will produce the cemented interface. The curves of this interface are...
light quantumThe individual coherent series of lightwaves that defines a quantum of radiant energy. Light quantum is equal to hv, h being...
hyperchromic shiftHyperchromic shift refers to an increase in the absorption of light, leading to a higher absorbance, often observed in...
flexible displayA flexible display refers to a type of electronic visual display that is designed to be bendable, foldable, or rollable,...
Cerenkov radiationThe radiation produced when a charged particle traverses a medium that has a refractive index considerably greater than...
dielectric coated gratingA shallow, fine-pitch diffraction grating having a precise dielectric overcoating that experimentally has absorbed...
hot mirrorA mirror with a coating that reflects infrared radiation and transmits visible light.
flat panel displayAn electronic display in which a flat screen is formed by an orthogonal array of display devices, such as electroluminescent...
focused laser scatteringA single-particle scattering technique in which an incident laser beam is tightly focused by means of lenses to yield a...
optical coherence tomography imaging systemOptical coherence tomography (OCT) is an imaging technique used in medical diagnostics and biomedical research to obtain...
phosphor light sourceA source made to glow by electrons that are produced either electrically or by isotopes of various elements.
microlens arrayA microlens array is a grid-like structure composed of numerous small lenses, typically arranged in a regular pattern. Each...
mixingCombining light beams, usually of unlike frequencies, to form a single beam with a frequency that is equal to the frequency...
Lummer-Gehrcke plateA high-resolution spectroscopic device commonly used in the early 20th century as a component of double-beam...
interferometerAn instrument that employs the interference of lightwaves to measure the accuracy of optical surfaces; it can measure a...
microwave holographyThe holographic recording of the pattern formed by two sets of coherent microwaves that interfere at a scanning plane. A...
electro-optic shutterA device used to control or block a light beam by means of the Kerr electro-optical effect.
diathermic mirrorA mirror coated to reflect cold (white) light while transmitting hot (infrared) energy.
absorption hologramA hologram formed when the light of the illuminating beam is absorbed in correspondence with the recording exposure. In...
telescope lensA telescope lens is a primary optical component of a telescope system that gathers and focuses light to form an image. It is...
solid opticsOptical elements arranged with no spaces between, so that the light travels only through glass, not air.
lensA lens is a transparent optical device that focuses or diverges light, allowing it to pass through and form an image. Lenses...
optoelectronicsOptoelectronics is a branch of electronics that focuses on the study and application of devices and systems that use light...
reflection gratingA reflection grating is an optical component that consists of a series of closely spaced, parallel reflecting surfaces or...
laser speckleSparkling granular pattern that is observed when an object diffusely reflects coincident laser light. Speckle appears as an...
night-vision deviceA device that uses low-level visible radiation or infrared radiation to produce a visual image of a night scene. These...
half-wave voltageThat voltage required across a Pockels, Kerr or other electro-optic light modulator to retard one polarization electrical...
autofluorescenceAutofluorescence refers to the natural emission of fluorescence exhibited by certain biological structures or molecules when...
nanoAn SI prefix meaning one billionth (10-9). Nano can also be used to indicate the study of atoms, molecules and other...
mask1. A framelike structure that serves to restrict the viewing area of the screen when placed before a television picture...
optical ceramicsTransparent glassy and or crystalline structured materials engineered from inorganic, non-metallic materials via various...
fluorescent proteinFluorescent proteins are proteins that exhibit the property of fluorescence, which is the ability to absorb light at a...
isotopically selected laser spectroscopyA spectroscopic technique in which an excitation band absorbs laser energy resulting in an electronic transition. The...
dichroic polarizerA polarizer that consists of dichroic polarizing material embedded in a plastic sheet, and that transmits light that is...
interferometric modulator displayInterferometric modulator display (IMOD) is a type of display technology used in electronic devices, known for its energy...
linear image sensorA linear image sensor is a type of solid-state electronic device used to capture and convert light into electrical signals....
cylindrical lensA cylindrical lens is an optical component that has different curvatures along its two orthogonal axes, resulting in a shape...
fiber optic transceiverA fiber optic transceiver, often simply referred to as an "optical transceiver," is a device used in fiber optic...
Schlieren photomicrographyThe photomicrographic recording of Schlieren effects, irregular refractions of light from optic surfaces or areas of thin,...
photosensitizerA substance that increases a material's sensitivity to electromagnetic irradiation. In photodynamic therapy, a drug used to...
aspheric mirrorAn aspheric mirror is an optical mirror surface that deviates from the shape of a perfect sphere, having a non-spherical...
nanoparticle photonic resonator absorption microscopyNanoparticle photonic resonator absorption microscopy is a microscopy technique that combines the principles of photonic...
speckle imagingA technique for obtaining improved resolution of images produced by large telescopes and distorted by the effects of...
atmospheric attenuationThe reduction in luminance of a light beam due to absorption and scattering as it passes through the atmosphere.
light source efficiency
Bunsen-Roscoe lawThe law stating that the amount of chemical change produced is proportional to the amount of light absorbed. Actually, the...
parametric oscillatorA device using a parametric amplifier inside a resonant optical cavity to generate a frequency-tunable coherent beam of...
Munsell valueNumerical scale of lightness devised by A.H. Munsell and exhibited in the Munsell Book of Color.
photographic shutter efficiencyA measure of the total light passed by a shutter during an exposure, compared with the light that could be passed by an...
rotary laserA structured light device using a rapidly rotating laser to project a beam of light that appears to the human eye as a...
vertical incident illuminationWith respect to microscopy, light that is directed down through the objective onto the specimen and then returned by...
thin-film coatingThin-film coatings are layers of material applied to the surface of an object or substrate, typically to modify its optical,...
quantum sensingQuantum sensing refers to a class of sensing technologies that leverage principles from quantum mechanics to enhance the...
solid-state light valveA light valve that uses a crystal as the control layer medium and that operates on the principle of the electro-optic effect.
biostimulationThe action of a biological system responding to a single or multiple coherent particles of light produced from a laser...
CMOS image sensorA CMOS image sensor, short for complementary metal-oxide-semiconductor image sensor, is a type of semiconductor device used...
Nernst glowerA Nernst glower, also known simply as a Nernst lamp or Nernst filament, is a type of incandescent lamp or radiant heater...
optics of materialThe area of optics that deals with the interaction of light with a given material. The optical properties of material are...
photodynamic therapyA medical technology that uses lasers or other light sources in combination with photosensitizing drugs to treat cancerous...
transducerA transducer is a device or component that converts one form of energy into another. It is commonly used in various fields,...
arc spectrumThe spectrum of the light produced by vaporizing an element in an electric arc.
discriminationThe degree to which a vision system is capable of sensing differences in light intensity between two regions.
fluorescenceFluorescence is a type of luminescence, which is the emission of light by a substance that has absorbed light or other...
electro-optic deflectionThe effect whereby a light beam is deflected by a birefringent prism when its polarization is changed by voltage applied to...
reconstructed imageAn image that appears when a hologram is illuminated by a suitable light source, generally a laser beam.
Williams refractometerA refractometer that has a greater resolving power than a standard refractometer, and that uses a pentagonal prism to split...
diffraction patternThe interference pattern formed by light waves diffracted at the edges of an object as seen on a screen placed in their path.
frustrated total reflectionLight leakage at a total reflecting interface when another highly refractive medium is brought close to it.
multijunction deviceA photovoltaic device that consists of multiple p-n junctions to produce a greater efficiency when in use than that of...
nonlinear optical detectorA type of radiation detector designed to recognize nonlinear optical effects, such as the Raman effect, by means of a...
flashlampA device that converts stored electrical energy into light by means of a sudden electrical discharge.
dark-field microscopyA technique whereby the sample is illuminated by a hollow cone of light larger than the acceptance angle of the objective,...
dark-field illuminationThe transmission of light by a condenser to observe either very small particles or very fine lines with a microscope.
photosynthetically active radiationPhotosynthetically active radiation (PAR) is the 400- to 700-nm region (visible light) of the electromagnetic spectrum that...
mercury vapor light sourceA lamp that has mercury in a tube or bulb that has first been evacuated. The electricity travels through the vapor between...
image-enhancing equipmentComplex devices, often involving a computer, in which a photograph is scanned by a point of light, the amplitude of the...
automated optical inspectionAutomated optical inspection (AOI) is a technology used in manufacturing processes, particularly in electronics, to...
light source powerThe electrical power used to stimulate any light source. Power supplies may be step-up or step-down transformers; rectifiers...
photomagnetic effectThe direct influence of light on the magnetic susceptibility of particular materials.
holographic optical elementA component used to modify light rays by diffraction; the HOE is produced by recording the interference pattern of two laser...
microbend-modulated sensorA type of fiber optic sensor that detects changes in pressure, vibration, sound level or acceleration by monitoring the...
photolysisThe photochemical reaction of light present in the decomposition of a substance.
electron trapping optical memoryA method of erasable optical data storage in which information is stored by visible light, then read by illumination with an...
Poisson shot noiseA stationary noise that occurs for visible light photodetection when a steady light source, such as a heterodyne reference...
alphanumeric readerAn instrument that reads alphabetic, numerical and special characters by means of a photosensor that measures the varying...
light sectioningTechnique for measuring the volume bulk of materials as they move along a conveyor with an accuracy of better than 1...
cathodoluminescenceLight produced when a metal is bombarded with high-velocity electrons causing small amounts of the metal to vaporize and...
central obstructionIn a reflecting telescope, the obstruction of the primary mirror by a secondary mirror which blocks a small amount of the...
optical testing instrumentAn optical testing instrument is a device or system used to evaluate and measure the performance, quality, and...
infrared light sourceAn infrared light source is a device that emits light in the infrared spectrum, which lies beyond the visible spectrum of...
whispering gallery modeWhispering gallery mode (WGM) refers to a phenomenon in wave physics, particularly in optics, where waves, such as light or...
Fabry-Perot interferometerA multiple-beam interferometer, usually consisting of two flat plates, with high reflective ability. The plates are set...
ultraviolet microscopyThe study and photographing of microscope specimens in ultraviolet light; using an optical microscope containing fluorite...
Sabattier effectThe reversal of a developed image due to the exposure of the partially developed image to actinic light.
holographic gratingA holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists...
loomingA form of mirage where objects near or just below the horizon appear in enlarged or distorted form because of atmospheric...
fiber optic preformA fiber optic preform is a cylindrical glass rod or tube used as the starting material for manufacturing optical fibers. It...
bundleA conical or cylindrical package of light rays emanating from a common point on the object.
evaporagraphA sensor generally used for infrared imaging. It consists of two chambers separated by a thin, blackened membrane. An...
scotoscopeAn instrument that uses an image intensifier to aid in the viewing of subjects in low-light-level environments.
polarizerAn optical device capable of transforming unpolarized or natural light into polarized light, usually by selective...
total image runoutImage displacement by a decentered lens, rotated on a chuck whose axis of rotation passes through the geometrical center of...
pinhole cameraA lensless photographic camera that uses a small sharp-edged hole as its aperture. The light passed by this aperture onto...
law of BrewsterThe law stating that when light strikes a surface at such an angle that the reflected and refracted rays are perpendicular...
artificial pupiliris or adjustable radially symmetric opening used for allowing the passage of useful light
Fermat's principleThe principle that a light ray extending from one point to another will, after any number of reflections and refractions,...
indium phosphideIndium phosphide (InP) is a compound semiconductor material composed of indium (In) and phosphorus (P). It belongs to the...
objectiveThe optical element that receives light from the object and forms the first or primary image in telescopes and microscopes....
Brewster's fringesThe fringes used in the Jamin interferometer and produced by light that has been internally and externally reflected by two...
polaritonA polariton is a quasiparticle resulting from the strong coupling between photons (light particles) and certain types of...
optical cements and adhesiveOptical cements and adhesives are specialized materials used in the assembly and bonding of optical components in optical...
convergence1. In optics, the bending of light rays toward each other, as by a convex or positive lens. 2. Turning in the eyes to view a...
PIN photodiodeA PIN photodiode is a type of photodetector or semiconductor device used to convert light signals into electrical signals....
projecting core couplerA device that couples a light source to an optical fiber by projecting an image of the source and the fiber core onto a...
laser cavityA laser cavity, also known as an optical cavity or resonator, is a fundamental component of a laser system. It is a confined...
himawariA system of Japanese origin that utilizes Fresnel lenses and a fiber optic network to transmit sunlight to otherwise...
fluorescence lifetimeFluorescence lifetime refers to the average time it takes for a fluorophore, a molecule that absorbs light at one wavelength...
open-dish methodA measurement method for reflectance by gas ionization in which light passes through a vapor before and after reflection....
visually coupled airborne systems simulatorA visual system including a tiny television tube and imaging optics, all contained in a helmet to be worn by pilots in...
Newton's ringsThe series of rings or bands formed when light beams reflected from two polished, adjacent surfaces, placed together with a...
diffraction fanningThe formation of a fan of light or energy rays in a beam as the beam passes through an extremely narrow aperture.
ultraviolet-visible spectrometerAlso known as UV-VIS spectrometer, a device that measures the absorbance, reflectance or transmittance of light in the...
holmium laserHolmium lasers are a type of medical laser that utilizes holmium-doped crystals as the gain medium. The term holmium laser...
electrophotographyThe photographic recording of an image formed by the alteration in electrical properties of the sensitive materials and...
photographic sound recorderA system in which the electrical signal embedded within an audio input signal is converted to a modulated light pattern and...
octaveIn optics, an octave typically refers to a range of frequencies or wavelengths that spans a factor of 2. In other words,...
cascade image tubeAn image tube that functions in low-light-level conditions by virtue of its series of stacked sections wherein the output of...
differential interference contrast microscopyDifferential interference contrast (DIC) microscopy, also known as Nomarski interference contrast microscopy, is an optical...
Kapitza-Dirac diffractionThe diffraction of a particle by a standing lightwave.
short wavelength infraredShort wavelength infrared (SWIR) refers to the portion of the infrared spectrum that encompasses wavelengths roughly between...
solar simulationThe simulation of solar radiation in the infrared and ultraviolet spectrum for the analysis of extraterrestrial sunlight and...
nominal hazard zoneZone of laser operation in which the direct, reflected or scattered light exceeds the laser's MPE and (by ANSI standards)...
sunlight recorderAn instrument consisting essentially of a photoelectric cell filtered to respond to a specified wavelength region, an...
chromaticityThe qualities of color associated with hue and saturation, but not brightness or lightness.
photonic crystal surface-emitting laserA photonic crystal surface-emitting laser (PCSEL) refers to a type of laser diode that emits light from its surface rather...
micro-ring resonatorA micro-ring resonator is a compact optical device that utilizes the resonant behavior of light within a small ring-shaped...
biprismA piece of glass polished flat on one side, with a pair of polished faces that form an angle close to 180° on the other...
mean spherical intensityThe average intensity of a light source measured over all directions.
infrared opticInfrared optics refer to optical components and systems designed to manipulate and control infrared (IR) light, which lies...
sapphire windowA sapphire window refers to a transparent optical component made from sapphire crystal. Sapphire is a single-crystal form of...
circularly polarized lightA light beam whose electric vectors can be broken into two perpendicular elements that have equal amplitudes and that differ...
coherent noiseThe manifestation of light from scatterers outside the plane of the object in coherent light systems. The output of these...
Kerr cellA cell filled with a transparent material that, when placed in a strong electrical field, exhibits double refraction. Since...
dispersion-flattened single-mode fiberA type of glass optical fiber that provides low pulse dispersion over a broad portion of the light spectrum and as a result...
phototheranosticsPhototheranostics, a portmanteau of "photo" (light), "therapy," and "diagnostics," refers to an emerging field that combines...
Boys cameraA camera system for recording lightning.
light beating
krypton lampAn arc lamp that has its cavity filled with krypton to produce a light source with unique characteristics.
twisted nematic phaseA form of liquid crystal widely used in displays, achieved by sandwiching a liquid crystal material between two substrates...
reticleA reticle, also known as a reticule or graticule, is a pattern or set of markings placed in the focal plane of an optical...
metamaterialMetamaterials are artificial materials engineered to have properties not found in naturally occurring substances. These...
dot matrix displayA display format consisting of small light-emitting elements arranged as a two-dimensional array. Various elements are...
fast axisIn a birefringent material, the index of refraction varies with the direction of vibration of a lightwave. That direction...
photon tunneling microscopeAn instrument in which visible light beyond the critical angle from a metallurgical microscope is focused on a reference...
prism couplerAn instrument that measures the angle at which a prism can couple laser light into an optical waveguide; used to determine...
halogen lampA halogen lamp, also known as a tungsten halogen, quartz-halogen, or quartz iodine lamp, is an incandescent lamp that uses a...
Casimir forceThe Casimir force is a quantum phenomenon that results in an attractive force between two closely spaced uncharged...
Nicol prismA prism invented by William Nicol in 1828 that is made of calcite, the end faces of which are ground to an angle of 68°...
rainbow hologramEssentially, a hologram of a hologram, in which the first-generation hologram is masked with a narrow slit. During image...
dark fiberUnused fiber; fiber that has been installed but reserved for future use. Carrying no light.
plasma laserOperates with light collectively emitted by the recombination of free electrons and ions in the plasma state.
Sellmeier's equationAn equation that uses the wavelength of light passing through a medium, along with a set of coefficients, to calculate the...
ultrasonic stroboscopeA light-interference device whose excitation is determined by the modulation of a light beam by an ultrasonic field.
CCD image sensorA CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images...
optoelectronic shutterA device used to control or block a light beam by means of the Kerr electro-optical effect, and other electro-optic devices...
dark-field condenserA condenser that forms a hollow cone-shaped beam of light with its focal point in the plane of the specimen. If it is used...
sun-tracking concentratorControlled beam technology that introduces beams of sunlight through holes in a roof that are relayed throughout the...
extinction1. The near total absorption of plane-polarized light by a polarizer that has an axis perpendicular to the plane of...
photometryPhotometry is the branch of science that deals with the measurement of light, particularly in terms of its intensity and the...
interference spectrumThe spectrum produced by the interference of light provided that the source used to create the interference has a broad...
virtual imageAn image that is formed when rays emerging from an optical system are diverging from the optical axis. The virtual image is...
photon couplingThe coupling of two circuits by the use of a light pipe through which photons are transmitted.
optoacousticOptoacoustic, or photoacoustic, refers to a phenomenon and related techniques that involve the generation of acoustic waves...
holographic tomographyHolographic tomography is an advanced imaging technique that combines holography and tomography to provide three-dimensional...
ophthalmic instrumentsA family of specialized instruments used by ophthalmologists and optometrists to study a patient's eyes and prescribe...
circular dichroismCircular dichroism (CD) is a spectroscopic technique used to study the structural characteristics of chiral (asymmetric)...
spectral centroidAverage wavelength usually determined for light-transmitting devices by taking a weighted average for each wavelength of the...
actinicStimulating light used for the production of energy through photosynthesis, solar cell or other light senstitive device.
flareNonimage-forming light, concentrated or diffuse, that is transmitted through the lens to the image. It is frequently the...
exposure meterAn instrument used to measure the light from a scene to be photographed and to indicate the camera lens and shutter settings...
alexandrite lasersAn alexandrite laser is a solid-state laser that utilizes a synthetic crystal made from the rare earth element alexandrite...
compensatorAn optical element that measures the phase difference between two components of elliptically polarized light to correct for...
curingThe use of chemicals or radiation to induce a desired change in a substance; e.g., some optical adhesives are set by...
photoelectric pyrometerAn instrument used to measure the temperature of a source through the use of photoelectric cells to detect and measure the...
ocular accommodationThe physical adaption of the eye lens, by means of ciliary muscle contraction, in order to maintain a clear, in focus image...
longitudinal field modulatorPockels cell or dynamic optical retarder in which the electrical field is applied in a direction parallel to that of light...
active-matrix OLED displayAn OLED display that has an integrated electronic backplane as its substrate. Active-matrix OLED displays use at least two...
fiber optic windowThe face of a cathode-ray tube (CRT) that has a fiber optic sheet attached to its surface. The sheet's fibers are at right...
photomicrographyThe use of a microscope in photographing objects. A device for photomicrography includes a light source, microscope and...
diffusing screenIn printing, a translucent screen used with lenses to provide an even distribution of diffused light.
dichroic mirrorA dichroic mirror, also known as a dichroic beamsplitter or interference filter beamsplitter, is an optical device that...
lumiaA laser effect used especially for laser light shows. Lumia are created by placing a distorting medium such as rippled glass...
polarizationPolarization refers to the orientation of oscillations in a transverse wave, such as light waves, radio waves, or other...
optically isotropic crystalA transparent crystalline substance that displays the same optical properties (i.e. refractive index) in all directions such...
field lens1. A lens situated at or near the plane of an internal image to project the aperture of a previous objective or erector upon...
rodThe light-sensitive cells on the retina of the eye that are responsible for low-resolution, peripheral vision.
lens testing equipmentLens testing equipment refers to a range of specialized tools and instruments used to evaluate the optical performance,...
shutterA mechanical or electronic device used to control the amount of time that a light-sensitive material is exposed to radiation.
modulator crystalA nonlinear crystal used to modulate a polarized beam of light by means of the Pockels effect. A Pockels cell is used as a...
fiber laserA fiber laser is a type of laser in which the active gain medium is an optical fiber doped with rare-earth ions such as...
Cornu-Jellet prismA prism formed by dividing a Nicol prism in a plane parallel to the path of vibration of the transmitted light and taking...
point spread functionThe point spread function (PSF) is a fundamental concept in imaging that describes the response of an imaging system to a...
optogenetic defibrillationAn optogenetic technique that embeds genetically-engineered proteins to the heart to aid in terminating arrhythmias. After...
machine vision lightingMachine vision lighting refers to the use of specific lighting techniques and equipment in the field of machine vision,...
scalar diffraction theoryScalar diffraction theory is a simplified approach used to describe the propagation of electromagnetic waves, particularly...
charge-injection deviceA charge-injection device (CID) refers to a class of devices that manipulate and detect electrical charge within a...
flying spot microscopeA microscope that uses a flying spot scanner, directed through the eyepiece, as a light source to determine the features of...
photoglow tubeA particular type of phototube having increased sensitivity as a result of the glow initiated by light incident to the...
packing fractionThe ratio of the active core area of a fiber bundle to the total area at its light-emitting or receiving end.
mode filterA device used in measuring the attenuation of multimode optical fibers. A short reference length of fiber when combined with...
Fourier transform hologramA hologram formed by the recording of a plane object situated in the focal plane of a lens so that each object gives rise to...
film recorderAn instrument designed to place nongraphic information, usually generated by a computer, onto photographic film. The...
cathode-ray tube envelopeEnvelopes for cathode-ray tubes are made by blowing glass in the same manner as light bulbs. They have a fairly flat end...
bellowsIn optics, a collapsible structure situated between the lens and film of a camera to allow variation of the distance between...
halo1. The faintly hued ring that is seen to surround a light source viewed through fog or light clouds. The size of scattering...
photoelasticityThe process of determining, with the aid of plane-polarized light, the stress distribution in materials under complex...
laser-induced fluorescenceLaser-induced fluorescence (LIF) is a spectroscopic technique that involves using a laser to excite molecules or atoms,...
antihalation backingLight-absorbing material that is applied to the back support of any bright image under inspection to prevent the formation...
photoresistPhotoresist is a light-sensitive material used in photolithography processes, particularly in the fabrication of...
laser active elementsLaser active elements typically refers to the substances or materials within a laser system that play a critical role in the...
diffuse illuminationLight emitted by one or more sources and characterized by a high degree of scatter.
ray tracingRay tracing is a rendering technique used in computer graphics to simulate the way light interacts with objects in a scene....
laser lithotripterA laser device intended for crushing urinary tract stones so they can be flushed from the body. Light is introduced via...
Callier effectThe selective scattering of light as it passes through a diffusing medium.
biprism interferenceLight interference fringes that can be viewed on a screen near a biprism.
optical data storageThe storage of information via optical means, primarily employing a low-power laser to inscribe data on a photosensitive...
physical opticsThe branch of science that treats light as a wave phenomenon wherein light propagation is studied by wavefronts rather than...
stimulated thermal scatteringLight from a pulsed laser focused into nonsaturable absorbing fluid that generates a strongly backscattered light beam with...
ring-laser gyroscopeA ring laser gyroscope (RLG) is a type of gyroscope that uses laser light to detect and measure changes in orientation. It...
point cloudA point cloud is a set of data points in a three-dimensional coordinate system, where each point represents a specific...
dichroismDichroism refers to the property of certain materials to exhibit different colors or absorbance of light depending on the...
excitonAn exciton is a quasiparticle that represents the bound state of an electron and a hole in a solid-state material, typically...
ophthalmoscopeAlso referred to as a funduscope, an ophthalmoscope is a specialized instrument used by ophthalmologists for observing and...
artificial starA point source of light used for the test and evaluation of image quality. May be a backlit pinhole in an otherwise opaque...
incident rayA ray of light that falls upon or strikes a surface of an object such as a lens. It is said to be incident to the surface.
integration timeIntegration time, in the context of optics, imaging systems, and sensor technology, refers to the duration over which a...
polycarbonateA tough, durable, heat- and cold-resistant optical quality plastic used in injection-molded items such as streetlight...
diffuse sensing modeUse of a photoelectric receiver to sense an object's presence by detecting a small amount of the emitter's light that is...
Arago spotA bright spot or point, due to Fresnel diffraction, that appears at the center of the shadow of a circular object in light...
transient calorimetric techniqueA method of measuring total hemispherical emissivity of the plane surface of a solid that consists of thermally isolating a...
degree of coherenceA quantitative measurement of the coherence of a light source; equal to the visibility (V) of the fringes of a two-beam...
diaphragmA flanged or plain ring with a restricted aperture, located in an optical system at any of several points, that cuts off...
photochemicalThe term photochemical pertains to chemical processes or reactions that are initiated or influenced by the absorption of...
FTIR spectrometerFTIR (Fourier transform infrared) spectrometer is a powerful analytical instrument used to obtain an infrared spectrum of...
Rayleigh scatteringRayleigh scattering is a phenomenon that occurs when light waves interact with particles or molecules that are much smaller...
lux-secondSI unit of light exposure.
anomaloscopeAn optical instrument that uses a yellow light of varying intensity with red and blue lights of fixed intensity to test for...
spectroradiometerA spectroradiometer is a device used to measure the intensity of light at different wavelengths across the electromagnetic...
Raman effectWhen light is transmitted through matter, part of the light is scattered in random directions. A small part of the scattered...
polychromatic acousto-optic modulatorA crystal-based device that combines and adjusts the intensities of multiple wavelengths of laser light in order to obtain...
optically active materialA material that can rotate the polarization of light that passes through it. An optically active material exhibits different...
angular spectrum approachThe angular spectrum approach is a mathematical and computational technique used in the field of optics to analyze and...
fatigueThe decrease of a component's efficiency, or a reduction in a material's light sensitivity, as the result of accumulated...
direct transmissionLight transmission involving no scatter.
Nichols radiometerAn instrument devised by Nichols and Hull for use in the measurement of radiation pressure. The device has two small...
reflectance confocal microscopyReflectance confocal microscopy (RCM) is a non-invasive imaging technique that allows for high-resolution, in vivo imaging...
x-ray image intensifierAn image intensifier that consists of an evacuated tube with a large input phosphor screen at one end. The phosphor screen...
Mie scatteringMie scattering, named after the German physicist Gustav Mie, refers to the scattering of electromagnetic radiation (such as...
off-axis paraboloid and ellipsoid mirrorOff-axis paraboloid and ellipsoid mirrors are specialized optical components used in various optical systems, particularly...
plastic opticsPlastic optics refers to optical components or systems that are made from transparent plastic materials, as opposed to...
maserAn acronym for microwave amplification by stimulated emission of radiation. Predecessor to the laser, the maser or...
indium gallium arsenide cameraAn InGaAs (indium gallium arsenide) camera is a type of imaging device that utilizes InGaAs sensors to capture images in the...
backlight compensationThe ability of a camera to compensate in cases where a subject with a large amount of background light would otherwise be...
highlightThe portion of a reproduced image having the greatest luminance.
occluderA device that completely or partially restricts the amount of light reaching the eye.
optoisolatorAn optical coupling device that uses light to bridge the gap between incompatible wire communications systems. It contains...
mercury arcAn electric arc that is formed in mercury vapor through which an electric current flows. The intensity of the illumination...
fluenceFluence is a term used in various scientific and technical disciplines to describe the amount of something per unit area....
critical angleThe least angle of incidence at which total internal reflection takes place. The angle of incidence in a denser medium, at...
machine vision lensA machine vision lens is a specialized optical lens designed for use in machine vision systems, which are used for automated...
light dispersionThe process whereby white light is separated into its component wavelengths. Light beams of different wavelengths are...
Foucault rotating mirrorA rotating mirror coupled with a distant mirror and used in a system by Foucault to compute the velocity of light. Light...
optical pumpingThe process whereby the number of atoms or atomic systems in a set of energy levels is changed by the absorption of light...
Risley prismA Risley prism, also known as a Risley prism pair or Risley rotating prism, is an optical device used for controlling the...
flight path deviation indicatorAn instrument designed to give a visual indication to the pilot when the plane has strayed from a specific flight path.
colorantA substance such as a dye or pigment that is used to alter the color of light.
phototransistor tachometerA tachometer consisting of a light source, rotating perforated wheel and phototransistor to measure the rates of rotation of...
zonal constantA factor that, when multiplied by the average candlepower emitted by a light source in a specified angular zone, reveals the...
incoherent bundleA bundle of filaments of optical glass or other transparent materials that transmit only light, not optical images. The...
Munsell color systemFounded by professor Albert Munsell. In the field of colorimetry, the Munsell color system is a color space that identifies...
acousto-optic modulatorA device that varies the amplitude and phase of a light beam; e.g., from a laser or by sound waves. Also known as a Bragg...
laser damageA natural or mechanical system adversely affected by the influence of laser radiation. During laser damage the common effect...
daylight lampAn incandescent or fluorescent lamp whose emittance spectrum resembles that of daylight.
window1. A piece of glass with plane parallel surfaces used to admit light into an optical system and to exclude dirt and...
spectroscopic flashThe light flash, produced in flash photolysis, that is triggered within a second discharge tube by the third electrode. It...
photoemissive tube photometerA photometer that uses a photoemissive tube to detect and measure light. See photoelectric photometry.
optical glassOptical glass refers to a type of glass specifically engineered and manufactured for use in optical components and systems,...
Fresnel fringeA single band in a group of light and dark bands that can be viewed in the periphery of Fresnel diffraction shadow.
diffraction gratingA diffraction grating is an optical component consisting of a surface with a periodic structure of equally spaced, parallel...
optical design softwareOptical design software refers to specialized computer programs used by optical engineers, physicists, and designers to...
deep-depletion CCDA CCD device for sensing longer wavelengths, such as NIR and IR, that has a deeper depletion region than would be necessary...
aplanatic pointsAplanatic points refer to specific points in an optical system where certain aberrations, such as spherical aberration or...
III-V materialIn semiconductor physics and materials science, the term "III-V materials" refers to compounds composed of elements from...
microphotonicsThe technology of manipulating light on a micro scale. In optical communications, this is usually accomplished using two or...
swept source optical coherence tomographySwept-source optical coherence tomography is an imaging technique used in medical diagnostics, particularly in...
Gudden-Pohl effectThe light flash that occurs when an electrical field is applied to a phosphor already excited by ultraviolet radiation.
nanophotonicsNanophotonics is a branch of science and technology that explores the behavior of light on the nanometer scale, typically at...
magnetic rotation spectroscopyTechnique in which the polarization rotation of light, and its relationship to the magnetic field strength can be analyzed...
quantum confinementQuantum confinement refers to the phenomenon in quantum mechanics where the motion of charge carriers, such as electrons or...
electro-optic modulatorAn electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an...
attenuationAttenuation refers to the gradual loss or reduction of intensity, force, or magnitude of a particular property as it...
claddingThe low-refractive-index material that surrounds the core of an optical fiber to contain core light while protecting against...
stochastic optical reconstruction microscopyStochastic optical reconstruction microscopy (STORM) is a superresolution microscopy technique that enables imaging of...
goniophotometerA device used to measure directional reflectance, with light collection restricted to a narrow range of angles of which the...
zodiacal lightThe sunlight that extends to the earth after scattering from other solar bodies, mostly from meteorite dust of radii...
laser strainmeterAn instrument usually consisting of a very long interferometer, 3 to 800 m, and a laser light source for the study and...
fiber-coupled LEDA fiber-coupled LED (light-emitting diode) refers to an LED device that is optically coupled to an optical fiber for the...
polarization-preserving fiberSingle-mode fiber that preserves the plane of polarization of the light launched into it as the beam propagates through its...
scintillation1. The variation in intensity of a light beam as it travels through the atmosphere. 2. In radiation physics, a light flash...
beam tableLaser light show effects equipment including optics and mechanical devices that reflect, position or distort the laser beam,...
autocollimatorAn autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on...
fluorescent light sourceA tube containing mercury vapor and lined with a phosphor. When current is passed through the vapor the strong ultraviolet...
atomic emission spectrometrySpectrometric analysis of the distinct and characteristic spectra of atoms of elements. The atoms are energized to emit...
free-electron laserA free-electron laser (FEL) is a type of laser that generates coherent, high-intensity electromagnetic radiation by using a...
lithographyLithography is a key process used in microfabrication and semiconductor manufacturing to create intricate patterns on the...
Geometrical opticsThe area of optics in which the propagation of light is described by geometrical lines (or rays) governed by Fermat's...
gravitational wavesPostulated by Einstein in his theory of relativity. They are waves traveling at the speed of light and exerting force on...
micro-LEDMicro-LED (micro-light-emitting diode) refers to a technology that involves the use of very small light-emitting diodes to...
randomized fiber optic cableFiber optic cable in which the arrangement of fibers within the bundle has been made random so that output light will be...
diode-pumped solid-state laserA diode-pumped solid-state laser (DPSSL) is a type of laser system that uses semiconductor diode lasers to pump energy into...
cadmium sulfideAn inorganic compound, yellow to orange in color, that fluoresces strongly enough when bombarded by a high-current-density...
relative brightnessA figure of merit corresponding to the amount of light seen by a viewer through binoculars. A higher number indicates a...
beatThe signal formed when two signals, such as light waves, of different frequencies are present simultaneously in a nonlinear...
cyanometryThe analysis of light in the blue region of the visible spectrum.
substage condenserIn a microscope, the optical assembly that focuses light on the specimen and into the objective.
optical encoderA device designed to measure linear or rotary motion by detection of the movement of markings on a transparent medium past a...
high dynamic rangeHigh dynamic range (HDR) refers to a technology that allows for a broader and more dynamic range of luminosity in visual...
ground glassA plate of glass in which a face has been frosted by grinding or etching. It diffuses light by scattering in directions...
infrared searchlightAn infrared source combined with reflecting projection optics to illuminate a target making it visible when observed through...
apochromatAn apochromat, often referred to as an apochromatic lens or apochromatic objective, is a type of optical system designed to...
leptonThe generic term describing the class of light particles having no strong interactions.
Tyndall coneThe form taken by scattered light, as a result of the Tyndall effect.
vertical transmitted illuminationWith respect to microscopy, light that is directed through the specimen by a substage condenser.
freeform opticsFreeform optics refers to the design and fabrication of optical surfaces that do not follow traditional symmetric shapes,...
lensless microscopyLensless microscopy, also known as computational or holographic microscopy, is an imaging technique that captures and...
eye guardA shield of rubber, plastic or metal used to protect the eyes of the observer from stray light and wind, and to maintain the...
infrared detectorAn infrared detector is a device that is used to detect and measure infrared radiation, which lies beyond the visible...
laser diode moduleA laser diode module is a compact device that incorporates a laser diode, optics, and often other components into a single...
galvo-directing mirrorsA system of mirrors that can be used to direct light from a single laser source into any one of a number of separate optical...
skew angleThe angle at which photoelectric sensors are aligned to prevent light from being reflected back to the sensor from the...
ultrafast pulsed laserAn ultrafast pulsed laser is a type of laser that emits extremely short pulses of light with durations typically on the...
Laurent polarimeterA Laurent polarimeter is an instrument used in optics for measuring the rotation of plane-polarized light caused by...
auto-iris lensA device for automatic exposure control in which a motor-driven diaphragm adjusts the aperture in response to a signal from...
microchannel plateA microchannel plate (MCP) is a specialized electron multiplier device used in various applications such as particle...
Mach bandsThe illusory appearance of a light or dark band at a line of brightness contrast that enhances the edge between the two...
Dove prismA form of prism invented by H.W. Dove. It resembles half of a common right-angle prism in which a ray entering parallel to...
ultramicrophotographyThe process of microphotography that involves the reduction of the original at a ratio greater than 100 to 1. The process is...
electromagnetic radiationRadiation emitted from vibrating charged particles. A combination of oscillating electrical and magnetic fields that...
crystal quartzThe naturally occurring crystalline form of silicon dioxide. It is slightly birefringent and exhibits rotary dispersion of...
photoreactive agentParticipates in a reaction only in the presence of light and radiant energy. Besides 3D printing, photoreactive agents also...
corneaThe transparent front layer of the eye. Light entering the eye is refracted (converged) by the outer surface of the cornea.
condenserA single positive lens or group of lenses used in a projection system to collect light from a source and cause it to...
surface-enhanced Raman scatteringSurface-enhanced Raman scattering (SERS) is a powerful analytical technique that enhances the Raman scattering signal of...
visual fault locatorA device that enables visual tracing of a fiber optic cable to check for breaks and defects by coupling visible light into...
Tyndall effectThe effect by which sufficiently small particles will scatter blue light at right angles to the incident beam. This...
circle of least confusionBest point of focus for an image in a beam of light at the smallest cross section of the beam.
photoelectric readerAn input device for a computer that detects and reads the data, in the form of punched holes in cards, by light that is...
reflected light meterAn exposure meter that indicates the amount of light reflected from the subject of interest.
beam shaperA beam shaper is an optical device or system designed to modify the spatial profile or intensity distribution of a laser or...
Rayleigh interferometerA device that is used to determine the index of refraction of a gas or liquid through the interference patterns formed by...
photonicsThe technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon. The...
black holeA cosmic phenomenon in which the mass and density of a star pass a critical point so that the escape velocity matches the...
Lippich prismA small half-shade analyzer placed in the eyepiece of a polarimeter to determine the character of the polarized light...
prism chromatic resolving powerThe chromatic resolving power of a prism is invariably stated for the case in which parallel rays of light are incident on...
fiber photometryAn optical recording technique that uses light source(s), a beamsplitting cube, light detector(s) and an optical fiber...
bioluminescenceHeatless light emissions from living organisms caused by the combination of oxygen and pigments such as luciferin.
aversion responseEye blink or head movement in response to bright light. Aversion responses such as blinking are sufficient protection from...
resonatorA resonator is a device or system that exhibits resonance, which is a phenomenon that occurs when an external force or...
phosphor persistenceThe property of a phosphor that determines its ability to emit light for a time after the stimulus has been extinguished....
flying spotThe moving spot of light emitted by a source, generally a cathode-ray tube, to illuminate specific points of an area...
nonlinear optical phase conjugationThe coupling of laser or light beams via nonlinear optical techniques such as four-wave mixing to achieve spatial variation...
femtosecond laserA femtosecond laser is a type of laser that emits ultrashort pulses of light with durations on the order of femtoseconds,...
dynamic light scattering spectroscopy
spatially offset Raman spectroscopySpatially offset Raman spectroscopy (SORS) is a technique that extends traditional Raman spectroscopy by incorporating...
active layerThat layer in a semiconductor injection laser or light-emitting diode that provides optical gain.
minimum perceptibleThe smallest object that may be seen, measured in terms of the angle subtended by the object measured at the eye. Also...
laser desorptionA process of forming ions within a given molecular species by incident laser light. The molecular species may remain intact,...
tip-enhanced Raman scatteringTip-enhanced Raman scattering (TERS) is a powerful technique that combines Raman spectroscopy with the enhanced spatial...
polarizing prismA device that is used to produce or analyze plane-polarized light. It may be a Nicol prism or some other form of calcite...
knife-edge scanning microscopeAn imaging device originally created to image whole mouse brain volumes at microscopic resolution. The main component of the...
optical comparatorTypically used for the examination of manufactured or engineered parts, an optical gauging device, in which a backlight is...
imageIn optics, an image is the reconstruction of light rays from a source or object when light from that source or object is...
Martens wedgeA wedge-shaped piece of quartz typically found in a polarimeter to monitor and rotate the plane of polarization of plane...
spatial light interference microscopySpatial light interference microscopy (SLIM) is an optical microscopy technique that belongs to the category of quantitative...
entrance slitThe entrance slit, also known simply as the slit, is an essential component in optical instruments such as spectrometers and...
asphericNot spherical; an optical element having one or more surfaces that are not spherical. The spherical surface of a lens may be...
Young's two-slit interferenceThe method by which Thomas Young in 1802 disproved Newton's corpuscular theory of light by the formation of interference...
macrobendingIn optical fiber, bends that are larger than microbends (see microbending), being visible. Generally they are caused by...
hematoporphyrin derivativeA material used in photodynamic therapy that is retained selectively by tumor tissue when injected into the body; it then...
meta-opticsMeta-optics, also known as metasurface optics or flat optics, is a branch of optics that involves the design, fabrication,...
cathode radiant sensitivityCathode radiant sensitivity refers to the ability of a photocathode to convert incident radiant energy, typically in the...
dust extinctionIn atmospheric optics, the almost total blocking of light transmission in the atmosphere due to the scattering and...
heterochromatic photometryLight measurement by comparison of the luminances of unlike chromaticities.
transmission planeIn polarized light, the plane of vibration that a polarizer will transmit.
objective prism1. A prism used in some instruments to bend light 90° before it enters the objective. 2. A dispersing prism located in...
harmonic generationHarmonic generation refers to a nonlinear optical process in which incoming photons interact with a material and produce new...
background luminanceThe intensity of the light in the scene behind an object being viewed.
contour analysisA method in optical character recognition in which a mobile light beam scans the outlines of characters for subsequent...
two-photon polymerizationTwo-photon polymerization (TPP) is a technique used in additive manufacturing, specifically in the field of 3D printing. It...
nonlinear optical effectA class of optical phenomena that can be viewed only with nearly monochromatic, directional beams of light, such as those...
drum cameraA type of streak camera that uses film wrapped around a drum, which moves at a constant speed to record the changing shape...
photonic cavityA photonic cavity, also known as an optical cavity, is a structure that confines electromagnetic radiation within a certain...
laser velocimeterA system that uses a continuous-wave laser to measure the velocity of an object by focusing the laser beam on the object,...
histologyHistology is the branch of biology and medicine that involves the study of the microscopic structure of tissues and organs...
path-reversal principleThe criterion maintaining that if light follows a specific path through an optical system, it will, if reversed, traverse...
image qualityA measure of the closeness with which an optical image is capable of resembling the original object. The factors that affect...
apparent contrastThe perceived brightness difference between light and dark areas on a target.
electroholographyA technology that uses electrically activated holograms stored within specially developed crystals to route information in...
laser crystalA laser crystal, also known as an active medium or gain medium, is a solid-state material used in the construction of...
overexposureThe improper exposure of a radiation-sensitive medium that results when there is too much radiation exposing the medium, or...
point light source1. With respect to angular subtense, a source of light, such as a star, that is very small. In a lab, a point source may be...
light fieldThe term light field refers to the spatial distribution of light rays traveling in all directions through a given space. It...
wide-field fluorescence microscopyWide-field fluorescence microscopy uses either naturally occurring structures or staining with fluorescent tags that are...
dark-line spectrumA spectrum having some lines that are darker than others or that contrast against a light, continuous-spectrum background.
optical tweezersOptical tweezers refer to a scientific instrument that uses the pressure of laser light to trap and manipulate microscopic...
optical transform image modulationA technique for detecting and measuring atmospheric pollution, in which an oscillating mirror directs half the incoming...
phototherapyPhototherapy is a medical treatment that involves the use of light to treat various conditions, particularly those related...
spectral line shiftA slight displacement in the position of a spectral line because of an alteration in frequency, as a result, in turn, of a...
emulsionIn photography, the layer of light-sensitive material (usually a suspension of silver halide crystals) that coats the film...
photoelectromagnetic effectInteraction of a magnetic field with a photoconductive substance exposed to light to create a potential difference.
optical bistabilityThe phenomenon that can render an optical resonator the equivalent of a semiconductor flip-flop. A bistable device will...
microprobeAn instrument that produces an intense, tightly focused beam of ions to stimulate emissions from a minute section of a...
anomalous photoconductivityA spectral phenomenon in which the degree of the photoresponse of an illuminated semiconductor is determined by the...
liquid-surface holographyThe acoustical holographic process in which the hologram consists of slight elevations in a liquid surface, in the areas of...
diode laserA diode laser is a type of laser that uses a semiconductor diode as the active medium to generate coherent light....
photobiomodulationA light therapy that utilizes nonionizing light sources, including lasers, LEDs, and broadband light, in the visible and...
multicolor hologramA hologram formed by reconstruction of multicolor wavefronts. The system used to produce the hologram is designed to combine...
conic refractionThe dispersion of a light ray striking the surface of a biaxial crystal, in which the resulting rays are reflected in a...
critical illuminationIllumination in which the light source is imaged at the object.
photopumpingThe use of light to initiate the lasing process. See optical pumping.
soft-focus lensA lens that exhibits spherical aberration when used at large aperture settings, and that forms an image with a slightly...
Iceland sparAlso called calcite. A natural hexagonal crystal of calcium carbonate. It cleaves readily into rhomboids useful in the study...
tissue opticsThe study of the optical properties of living tissue. Increased understanding of the behavior of light in this varied,...
solitonAny isolated wave that propagates without dispersion of energy. Specifically to photonics, an ultrashort pulse of laser...
impurity levelIn the context of optical materials, the term "impurity level" refers to the presence of foreign atoms or molecules within...
false color processEntirely analogous to color photography, but inclusive of light bands that do not appear in the visible spectrum.
light pencilA narrow cone of light rays that diverge from a point source or converge to an image point.
photoimmunotherapyPhotoimmunotherapy (PIT) is a medical treatment approach that combines elements of phototherapy and immunotherapy to target...
masks for evaporation/depositionIn the context of thin film deposition processes such as evaporation or sputtering, masks are used to selectively deposit...
azimuth angle1. In astronomy, the angle measured clockwise (eastward) in a horizontal plane, usually from north (true north, Y-north,...
near-infrared cameraA near-infrared (NIR) camera is an imaging device designed to capture images in the near-infrared region of the...
diffraction rings1. The ring patterns of light that seem to encircle particles in the field of a microscope. 2. See Newton's rings.
blur circleA blur circle refers to the out-of-focus region in an image captured by an optical system. When an object in a scene is not...
polygonal mirrorA polygonal mirror, also known as a multifaceted mirror or facet mirror, is a type of optical component used in various...
electron-beam film scanningThe method by which photographic film is scanned by an electron beam. One technique uses the uniform light of a television...
image dissector tubeAn electron tube that is used as a camera tube for a television system. When the picture to be transmitted is focused on a...
quantum wellA quantum well is a structure in quantum mechanics that confines particles, such as electrons or holes, in one spatial...
fiber optic spectrometerA fiber optic spectrometer is a device used for measuring the spectral content of light. It utilizes optical fibers to...
redshiftThe displacement of spectrum lines, as determined by the increasing distance between, and the relative velocity of, the...
nanoLEDAn LED (light-emitting diode) is a semiconductor device that emits light when an electric current passes through it. LEDs...
plasmonicsPlasmonics is a field of science and technology that focuses on the interaction between electromagnetic radiation and free...
attenuated total reflectance spectroscopyAttenuated total reflectance (ATR) spectroscopy is a technique used in analytical chemistry to obtain IR spectra of samples....
axial paraxial rayA paraxial light ray that extends from an object point on the optical axis.
nonradiative transitionA nonradiative transition refers to a process in which an electron or an atom undergoes a change in its energy state without...
white lightLight perceived as achromatic, that is, without hue.
emergent rayIn optics, the light ray leaving a medium in contrast to the entering or incident ray.
beam candlepowerWith relation to the equivalent beam candlepower of a searchlight, the candlepower of a bare source that would produce the...
latent imageThe pattern of physical or chemical changes that has taken place in a photographic emulsion, by its exposure to light, that...
scanningThe successive analysis or synthesizing of the light values or other similar characteristics of the components of a picture...
light meterAny device that is used to sense and measure light. See exposure meter; photoelectric exposure meter; photoelectric...
crystalA solid with a structure that exhibits a basically symmetrical and geometrical arrangement. A crystal may already possess...
astronomical mirrorAn astronomical mirror, also known as a telescope mirror or primary mirror, is a key component of a reflecting telescope. It...
phase screenA phase screen, in the context of optics and wave optics, refers to a surface or medium that introduces a phase delay to an...
quarter-wave plateA plate made of a double-refracting crystal having such a density that a phase difference of one-quarter cycle is formed...
allogyric birefringenceLeft- and right-hand circularly polarized beams that are produced at different velocities by passing plane-polarized light...
magneto-optic shutterA type of high-speed photographic shutter that uses Faraday rotation to produce exposure times as fast as 1 microsecond. It...
bias frameA frame taken with a CCD camera over an exposure length of zero seconds with the lens cap on or the shutter closed and no...
dichroscopic eyepieceAn eyepiece used in a polariscope or polarizing microscope to give a comparison view of the same object under illumination...
Brillouin scatteringBrillouin scattering is a phenomenon in physics where an incident electromagnetic wave (usually light) interacts with...
laser outputThe laser output refers to the generated and emitted light produced by a laser system. This output is characterized by...
photoacoustic imagingAbbreviated PAI. An imaging modality with a hybrid technique based on the acoustic detection of optical absorption from...
reflection x-ray microscopyA means of high resolution study through the application of soft and hard x-rays onto a sample surface in order to obtain...
magnetic vectorA term denoting the magnitude and direction of the magnetic field associated with an electromagnetic wave when describing...
liquid crystalLiquid crystals are a state of matter that exhibits properties intermediate between those of conventional liquids and solid...
chemiluminescenceA chemical reaction involving the production of light. The reaction of ethylene with ozone is chemiluminescent.
scanning headA device composed of a light source and phototube used to scan a moving strip of material in photoelectric side-register...
fiber-coupled photoconductive antennaA fiber-coupled photoconductive antenna (FCPA) is a type of optoelectronic device that combines a photoconductive antenna...
scaling lawIn coherence theory, an optical law put forth by physicist Emil Wolf that explains the behavior of light as it travels away...
light-beating spectroscopyThe spectroscopic analysis of optical line shapes and frequency shifts, using the technique of light beating; i.e., the...
mode-locked lasersMode-locking is a technique used in lasers to produce ultrashort pulses of light with durations on the order of picoseconds,...
semiconductorA semiconductor is a type of material that has electrical conductivity between that of a conductor and an insulator. In...
fluorescent screenA fluorescent screen refers to a phosphorescent or fluorescent-coated surface that emits visible light when exposed to other...
ospinOpsins are a group of light-sensitive proteins found primarily in the retinas of vertebrate and invertebrate eyes, as well...
hololensA series of permanent holograms in dichromated gelatin formed by opening total page-composer apertures and setting a point...
incandescenceThe emission of light by thermal radiation of a temperature high enough to render the source of radiation visible.
correction windowAn optical wedge of very small angles that admits light while sealing out moisture and dirt and that may be rotated to...
near-infrared spectrometerA near-infrared (NIR) spectrometer is an analytical instrument used to measure the absorption, transmission, or reflection...
stereoscopic visionVision in depth of three dimensions as a result of the spacing of the eyes. This spacing allows the eyes to see objects from...
baffleAn opaque shielding device designed to reduce the effect of stray light on an optical system.
laser opticsLaser optics refers to a broad category of optical components and systems designed for manipulating and controlling laser...
scintillation counterAn instrument designed to measure radiation indirectly through the use of several phosphors and a photomultiplier tube. The...
videographyVideography refers to the process of capturing moving images and recording them in a digital format. It involves the use of...
active regionThe layer of material in a laser diode from which the optical radiation is emitted; light producing region
electroluminescent-photoconductive image intensifierA panel of photoconductive and electroluminescent layers used as either a positive or negative image intensifier, depending...
GRIN lensA GRIN (gradient index) lens is a type of optical lens that utilizes a gradient in refractive index across its volume rather...
remote active spectrometerA device employed to identify toxic agents lingering on the ground or in the air from up to three miles away, by using laser...
lenticular screenA rear or front projection screen composed of minute optical surfaces that introduce a spread to the light beam that...
Gires-Tournois interferometerAn interferometer similar in construction to a Fabry-Perot interferometer but having a rear mirror with high reflectivity,...
flame photometerAny of a number of instruments that uses a flame to vaporize a solution of the chemical being analyzed so that light may be...
molecular motorA molecular motor refers to a nano-sized device composed of organic molecules or other small-scale components that can...
cadmium sulfide cellA photoconductive cell having cadmium sulfide as its photoconducting material for the production of a very high dark-light...
double refractionThe separation of unpolarized light into two plane-polarized elements by a doubly refracting crystal. When a crystal, such...
separate absorption and multiplication region avalanche photodiodeAn avalanche photodiode in which the light-absorbing area is a low-bandgap material and the PN junction is placed in an area...
far-field diffraction patternThe diffraction pattern of a source such as a light-emitting diode, injection laser diode or the output end of an optical...
fiber bundleA rigid or flexible, concentrated assembly of glass or plastic fibers used to transmit optical images or light. See aligned...
focusing corner cubeA retroreflector that can focus a beam of light, with one planar reflective surface, one spherical and a third that is...
half-wave plateA plate of electro-optical material that serves to rotate the plane of polarization of a light beam.
color scannerAn instrument that uses a beam of light to scan a color transparency, and three differently filtered photosensors to record...
transmitterIn fiber optic communications, a light source whose beam can be modulated and sent along an optical fiber, and the...
mirror blankA mirror blank refers to the initial piece of material from which a mirror is made. It is typically a flat or slightly...
notch filterAlso referred to as a band-stop or band rejection filter; a notch filter is a filter that is designed to screen out a very...
invisible light filterA filter that transmits infrared and ultraviolet but is opaque to visible radiation.
dye-polymer optical discA type of erasable data storage device that uses a medium deposited on the disc in two layers, each dyed to absorb a...
optical gratingAn optical grating, in the context of optics and physics, refers to a device with a periodic structure of closely spaced,...
Abbe condenserA two-lens arrangement intended to image light into a microscope slide sample. The primary aberrations present are red and...
additivity of luminanceThe luminance of a mixture of lights is the sum of the luminances of the component lights in the mixture.
optical camouflageThe use of retroreflective projection technology (RPT) to project a background image onto a masked object, such as a vehicle...
directed energyDirected energy refers to a type of energy that is emitted and transferred in a controlled direction. The term is often...
retroreflectorA retroreflector is an optical device or structure that reflects incident light or electromagnetic waves back to their...
near-infrared spectroscopy cerebral oximetryA monitoring technique used to measure the oxygen saturation levels in the brains of patients, commonly in operating room...
laser sparkBreakdown of a gas produced by the attenuation of an intense pulse of focused laser light.
solid-state laserA solid-state laser is a type of laser that uses a solid gain medium (as opposed to a liquid or gas) to produce coherent...
ultrashort-pulse laserA laser capable of generating light pulses that last only a few femtoseconds. This can be achieved by nonlinear filtering to...
electroluminescenceThe nonthermal conversion of electrical energy into light in a liquid or solid substance. The photon emission resulting from...
Kerr solitonA Kerr soliton refers to a specific type of soliton, a self-reinforcing wave packet, that arises in nonlinear optical...
phototoxicityPhototoxicity refers to the harmful effects caused by exposure to light, particularly intense or ultraviolet (UV) light, on...
Pechan prismA prism made up of two air-spaced components. It has the ability to revert, and not invert, an image, and can be used in...
collectorA positive lens located at or close to an intermediate image plane. The collector refracts off-axis light bundles, directing...
optical phase distortionOptical phase distortion refers to a phenomenon where the phase of an optical wavefront is altered as it propagates through...
radiant energyThe energy passed on as electromagnetic radiation; e.g., radio, heat or light waves.
sapphire optical fiberSapphire optical fiber is a type of optical fiber made from single-crystal sapphire, which is a form of aluminum oxide...
proximity effectThe underexposure caused by the diffraction of light passing through small openings spaced closely together in masks used in...
dark operate modeAn operate mode in which the sensor is programmed to perform a task such as generating output when the light level falls...
magnetic rotation spectrumThe absorption spectrum of an element influenced by a magnetic field in the same direction as the transmitted light, which...
footprint1. The sector of the Earth's surface registered upon a remote sensing device in a satellite. 2. The amount of space occupied...
Fizeau toothed wheelA device used to measure the speed of light by adjusting the rotation of a toothed wheel so that light passing through one...
photoelectric relayA relay that opens or closes an electrical circuit depending on the intensity of the light incident to a photoelectric...
heat-absorbing filterA glass filter that transmits visible light while absorbing infrared energy (heat).
white-light hologram
high harmonic generationHigh harmonic generation (HHG) refers to a nonlinear optical process in which intense laser light interacts with a gaseous...
germicidal UVGermicidal ultraviolet (GUV) refers to a specific range of UV radiation that has disinfectant properties capable of killing...
projection pointerA device used to project a small area of light on a screen for indication.
holographic cameraA holographic camera, also known as a holographic imaging system or holographic recorder, is a specialized device used to...
scanning electron microscopyScanning electron microscopy (SEM) is an advanced imaging technique used in microscopy to obtain high-resolution,...
light penA handheld, light-sensitive device that is used with a display console to directly change, measure or erase the visual...
image storage panelA modified form of an image-retaining panel that can be used in subdued daylight. This is achieved by adding a layer of zinc...
amplitude-modulated sensorA type of fiber optic sensor that detects alteration in position, distance, pressure, liquid level or temperature by...
nominal ocular hazard distanceThe calculated normal distance from a photon source at which harmful interaction with the incident light will occur....
metasurfacesMetasurfaces are two-dimensional arrays of subwavelength-scale artificial structures, often referred to as meta-atoms or...
low-light-level instrumentationInstrumentation designed to permit the perception, recording or measurement of scenes under conditions of low incident...
laser Doppler velocimeterDevice which determines particle velocity through the measurement of scattered interference of a beam pair from a single...
photonics contract manufacturingPhotonics contract manufacturing refers to the outsourcing of the production of photonics-related components, devices, or...
half-shade deviceA device for forming at least two adjacent areas of polarized light. The angle between the directions of vibration of the...
reduced focal lengthThe ratio of the first focal length of a lens to the refractive index of the medium containing the incident light; the ratio...
splitterA passive fiber optic coupler that divides light from a single fiber into two or more fiber channels.
embedded laserThe term "embedded laser" typically refers to a laser device that is integrated or embedded into a larger system or...
linear polarizationSee plane-polarized light; polarization.
short-flash light sourceAn electronic flash tube in which the flash recurs at a frequency extending to many thousands per second. A stroboscopic...
microscopyMicroscopy is a scientific technique that involves the use of microscopes to observe and study objects that are too small to...
bandgapIn semiconductor physics, the term bandgap refers to the energy range in a material where no electronic states are allowed....
ultraviolet reflectanceUltraviolet reflectance refers to the ability of a material or surface to reflect UV light. Ultraviolet light is...
negative-refraction metamaterialAn artificial material, engineered to have a negative refractive index value, such that light or any other form of...
eyeThe organ of vision or light sensitivity.
digital subtractionThe process by which the values of one digital image of an object or scene are removed from a second slightly different...
scintillation crystalA scintillation crystal, also known simply as a scintillator, is a material that emits light when it interacts with ionizing...
diffraction spectrumIn spectroscopy, the parallel bands that vary in lightness and darkness or color, and that are formed when light is...
achromatAn achromat, in the context of optics, refers to a type of lens or lens system designed to reduce chromatic aberration....
computer polarization holographyA technique used to store wavefront information on thin polarization information-recordable materials by controlling the...
surface-enhanced Raman spectroscopySurface-enhanced Raman spectroscopy (SERS) is an analytical technique that combines the principles of Raman spectroscopy...
optical fiberOptical fiber is a thin, flexible, transparent strand or filament made of glass or plastic used for transmitting light...
image photocounting distributionPhoton flow created by imaging of light into a detector array; IPD is the electrical signal used by the image processor in a...
interstitial absorbing coatingAn absorbing coating medium between fibers, used in some fused fiber optic plates to absorb unwanted light. Such coatings...
MEMS fiber optic switchA MEMS fiber optic switch is a microelectromechanical system (MEMS) device designed to selectively route optical signals...
light chopper
nonlinear opticsNonlinear optics is a branch of optics that studies the optical phenomena that occur when intense light interacts with a...
beam1. A bundle of light rays that may be parallel, converging or diverging. 2. A concentrated, unidirectional stream of...
infrared cameraAn infrared camera, also known as a thermal imaging camera or IR camera, is a device that captures and visualizes the...
degradationThe gradual decrease over time in output signal with constant input light level.
scatterometryA measurement technique used for the rapid quantitative evaluation of surface quality based on the detection and analysis of...
CMOS cameraA CMOS camera refers to an imaging device that employs a complementary metal-oxide-semiconductor (CMOS) image sensor to...
phase contrast microscopyPhase contrast microscopy is an optical microscopy technique that enhances the contrast of transparent and colorless...
iridescenceThe rainbow exhibition of colors, usually caused by interference of light of different wavelengths reflected from...
refracted rayA light ray that has had its direction altered because of its traversing an air-to-glass interface at some angle. In an...
InGaAs photodiodeAn InGaAs photodiode refers to a photodetector device that is constructed using a semiconductor material composed of a...
indium antimonideA semiconductor material that is used as an infrared detector for light up to 5 µm in wavelength.
chip-on-board lightsChip-on-board (COB) lights refer to a type of LED lighting technology where multiple LED chips are directly mounted onto a...
absolute refractive indexThe ratio of the speed of light in a vacuum divided by the speed of light in the medium.
responsivityThe gain that occurs between light intensity incident on a CCD given by the photocurrent produced.
laser microscopyTechnique using functional optical microscope with the addition of a coherent source collinear with the image path. The...
eye-safe laser operationWavelengths between 400 and 1400 nm (VIS to NIR) are focused onto the retina by the cornea. Because the retina is sensitive...
Airy differential equationThe equation devised by Sir G.B. Airy for the analysis of light diffraction near a caustic surface: (d2f/dz2) - zf = 0 where...
Fresnel mirrorsTwo plane mirrors that are not wholly located in the same plane. When light from a point source or slit reflects from the...
lightElectromagnetic radiation detectable by the eye, ranging in wavelength from about 400 to 750 nm. In photonic applications...
Hubner rhombA glass rhomb that is used in photometry to compare two illuminated surfaces. This is accomplished by the rhomb's angles,...
lateral shearing interferometerA lateral shearing interferometer is an optical device used in interferometry to measure phase differences between two beams...
riez photodiodeA photodiode having a conducting grid that covers the surface of the photodiode junction and intercepts and wastes some of...
coloring mediaTransparent media which, when placed in front of a light source, change their color as a result of the selective absorption...
pedestal componentPresent in photocurrent burst, it is the low frequency pulse that corresponds to the light scattered from the beams in the...
ringlightA circular lamp or bundles of optical fibers placed around the perimeter of an objective lens to illuminate the object field...
flame spectroscopyThe study of flames by means of a laser emitting blue light and a spectrometer to measure the green fluorescence created by...
focal pointThat point on the optical axis of a lens, to which an incident bundle of parallel light rays will converge.
photographic photometryA form of photometric measurement, often used with light sources that are transparent or fluctuating, in which a...
time-lapse optical coherence tomographyTime-lapse optical coherence tomography (OCT) refers to a medical imaging technique that captures a series of sequential OCT...
direct-vision prismAn assembly of multiple prisms that disperses incident light into its spectral components without deviating light at the...
photovoltaicPhotovoltaic (PV) refers to a technology that converts sunlight directly into electricity using semiconductors. The term...
edge-defined film-fed growthProcess for growth of solar cells that results in rectangular shapes consisting of many interconnected cells in a series or...
radiation angleHalf the vertex angle of the cone of light emitted by a fiber.
planar access couplerLow-insertion-loss fiber coupler fabricated from a sheet of light-sensitive material laminated onto a fused quartz substrate...
optical workThe degree to which the surface of a lens causes an incident ray of light to bend, or the amount of convergence or...
Linnik interference microscopeA Michelson-type interference microscope used to produce interference patterns of reflective specimens through the...
optical filterAn optical filter is a device that selectively transmits or blocks specific wavelengths, or colors, of light. Optical...
color aging testA test used to measure the degree of fading of different colored materials, especially those involving organic dyes, which...
optical rotation1. The angular displacement of the plane of polarization of light passing through a medium. 2. The azimuthal displacement of...
contact fluidA liquid, usually of a specific refractive index and dispersion, serving as an interface between two solids to form a...
fiber opticsThe use of thin flexible glass or plastic fibers as wave guides — or "light pipes" — to channel light from one...
electrostatic printerAn instrument used to print an optical image on a specially treated paper. Light and dark portions of the original image are...
color perception test equipmentEquipment for testing an observer's color vision. Some tests require the identification or ordering of colored samples. The...
plastic optical fiberPlastic optical fiber (POF) is a type of optical fiber made from transparent plastic, typically polymethylmethacrylate...
photoconductorA light-sensitive resistor in which resistance decreases with increase in light intensity when illuminated. The device...
free-space optical interconnectA type of internal photonic connection in an integrated circuit in which a holographic grating is used to focus light at...
waveguideA waveguide is a physical structure or device that is designed to confine and guide electromagnetic waves, such as radio...
direct illuminationLight produced by visible radiation that moves from the light source to the object without reflection. With respect to...
spot meterA telescopic light-sensing meter used to measure illumination levels of small regions at a distance of many feet; it is used...
microdisplayA microdisplay is a miniature electronic display technology that is designed to project visual information onto a small...
dark spaceThe portion of a glow discharge tube that permits little or no light transmission.
transparentCapable of transmitting light with little absorption and no appreciable scattering or diffusion.
linear receive opticsLinear receive optics typically refers to the optical components and systems used in the reception (detection) of linearly...
acousto-optic modulationThe altering of lightwaves by acoustic waves in a solid medium.
angular apertureThe angle between the most divergent rays that can pass through the lens to form an image. In a birefringent crystal light...
Kerr effectThe Kerr effect, named after the physicist John Kerr who first observed it in 1875, is a nonlinear optical phenomenon where...
electron opticsThe control of free electron movement through the use of electrical or magnetic fields, and use of this electron movement in...
white-light interferometer
PlumbiconPhilips trade name for a lead oxide low-light-level vidicon tube.
photomultiplier tubeA photomultiplier tube (PMT) is a highly sensitive vacuum tube that detects and amplifies low levels of light. It is widely...
dielectric lensA lens made up of a dielectric material that is capable of influencing radio waves much in the same way an optical lens...
isolatorIn the context of electronics and optics, an isolator refers to a device that allows the transmission of signals in one...
photoelasticIn optics, the double refraction that is produced when stress is applied to a transparent material. Plastics, which are...
optical Fourier transformThe optical Fourier transform is a mathematical operation applied to optical signals that involves transforming a spatial...
liquid lightguideAn optical fiber with a hollow core filled with a liquid material that has a higher refractive index than the solid...
chemical actinometerA light-sensitive detector having a chemical compound that reacts when exposed to light. It is used in photochemistry and...
triple mirrorAlso known as corner-cube reflector or retrodirective reflector. Three reflecting surfaces, perpendicular to each other,...
fluorescent whitening agentsAgents used for testing light sources and natural daylight with visual and instrumental assessment using a set of white...
topological photonicsTopological photonics is a branch of physics and optics that explores the application of topological concepts to the...
biophotonicsThe technology that deals with the interaction of organic materials with light and other forms of radiant energy whose...
exit angleThe angle between a light ray emerging from an optical system and the optical axis of that system.
virtual realityVirtual reality (VR) is a computer-generated simulation of a three-dimensional environment or experience that can be...
STED microscopySTED microscopy, or stimulated emission depletion microscopy, is a superresolution imaging technique in fluorescence...
blind spotThe spot on the retina where the optic nerve is attached; it is incapable of sensing light because of the absence of light...
intensified charge-coupled device cameraAn intensified charge-coupled device (ICCD) camera is an advanced imaging device that combines the capabilities of both an...
synchrotron radiationRadiation emitted by electrons when they travel in circular orbits at speeds close to that of light. Synchrotron radiation...
image plane holographyA hologram in which the image of an object, or the object itself, is located near the hologram recording plane, for optimum...
quartz light sourceA lamp with a quartz envelope that transmits radiation generally rich in the ultraviolet.
colorThe attribute of visual experience that can be described as having quantitatively specifiable dimensions of hue, saturation,...
Rayleigh criterion of resolving powerWhen a lens system with a circular aperture is free of aberrations, the image of a point object will appear as a disc of...
Seidel aberrationsSeidel aberrations refer to a set of monochromatic aberrations in optical systems, named after the German mathematician and...
orthochromatic filmBlack and white film that is sensitive to green, blue and violet light but not to red light.
integrated photonicsIntegrated photonics is a field of study and technology that involves the integration of optical components, such as lasers,...
scattering coefficientThe portion of light scattered when traveling through a unit thickness of material.
backlitRefers to a display or screen that is illuminated from behind; the light is transmitted as opposed to reflected.
circulatorA passive device, having three or more ports, in which input light from one port is coupled only to the next sequential port...
Stokes parametersThe parameters, relative to polarized light and the Poincaré sphere, that are usually represented as: I, the intensity of...
heliostatA device having a plane mirror so mounted that it can be set to reflect sunlight into a piece of laboratory equipment. It is...
Nipkow disc scannerA device consisting of a disc with a spiral arrangement of holes that is used to convert visible patterns into electrical...
dimmerAn electric or electronic device that regulates the voltage going to a light source as a means of varying the intensity of...
lightguide
distributed feedback laserA distributed feedback laser (DFB laser) is a type of semiconductor laser diode designed to emit coherent, narrow-bandwidth...
molded lensA molded lens is an optical lens manufactured using a molding process, typically involving the shaping of a material, such...
exposure indexA measure of film speed sensitivity to light.
rayA geometric representation of a light path through an optical device; a line normal to the wavefront indicating the...
atomic absorption spectrometerAn atomic absorption spectrometer (AAS) is an analytical instrument used to determine the concentration of specific chemical...
perceived colorThe apparent color, as seen by the human eye, as distinguished from color as a measurable property of light.
optical figureThe amount by which an optical surface deviates from its ideal design value, expressed in wavelengths of light. Optical...
functional near-infrared spectroscopyFunctional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging technique that measures changes in hemoglobin...
quantum opticsThe area of optics in which quantum theory is used to describe light in discrete units or "quanta" of energy known as...
color sensitometryThe detection and analysis of the relative response of a material to light over the range of wavelengths.
photomaskA photomask, also known simply as a mask or reticle, is a key component in the photolithography process used in...
half silveredDescribing a surface that is coated with a film of metal of such thickness that it transmits about one-half of the incident...
two-dimensional response kernelCharacteristic of an acousto-optic modulator, defined by the overlap integral of the incident light and sound field...
thermal interface materialsThermal interface materials (TIMs) are substances or compounds used to enhance the thermal conductivity between two surfaces...
electroluminescent displayThe utilization of the light produced when electrical energy is directly converted into light within devices used for visual...
lidarLidar, short for light detection and ranging, is a remote sensing technology that uses laser light to measure distances and...
gallium arsenide phosphideGallium arsenide phosphide (GaAsP) is a semiconductor alloy composed of gallium (Ga), arsenic (As), and phosphorus (P). It...
dominant wavelengthA single wavelength of light that matches the color of a given sample when combined in suitable proportions with white light...
structured illumination microscopyStructured illumination microscopy (SIM) is an advanced optical imaging technique used in microscopy to enhance the...
spectral flow cytometrySpectral flow cytometry is an advanced flow cytometry technique that expands the capabilities of traditional flow cytometry...
hole burningThe dip or gap in the profile of a laser beam's line width when it is both homogeneously and inhomogeneously broadened. When...
photomorphogenesisThe study of the effects of light on the growth and development of various plants.
photocoagulatorAn optical medical instrument that uses an intense, precisely focused beam of light to stop weakened blood vessels from...
ultramicroscopeA dark-field microscope used to view extremely small objects. These objects are suspended in a gas or liquid in an enclosure...
electro-optic transistorA transistor designed to respond to either light or electrical signals.
collimatorAn optical instrument consisting of a well- corrected objective lens or mirror with a light source and or object/image (i.e....
reflecting galvanometerA galvanometer having a small mirror that is mounted on a moving element and that reflects a light beam onto a scale.
gated pulseA discontinuous burst of laser light generated by timing or "gating'' a continuous-wave laser.
organic light-emitting diodeAn organic light-emitting diode (OLED) is a type of light-emitting diode (LED) technology that utilizes organic compounds to...
photoelectric counterA device used to count objects that pass a given point by allowing each object to obstruct a beam of light falling on a...
reference whiteThe light from a nonselective diffuse reflector due to the standard illumination of the scene to be televised.
retardanceThe degree of angular shift in the phase of incoming polarized light.
light sheet fluorescence microscopyAlso known as single plane illumination microscopy (SPIM), this process was designed for imaging of sensitive samples and...
electron image tubeA cathode-ray tube that increases the brightness or size of an image or forms a visible image from invisible radiation. The...
photodischarge spectroscopyA spectroscopic process that detects and analyzes the discharge from an extrinsic surface with less than bandgap light. This...
white balanceA feature of some imaging devices, such as digital cameras, that allows them to compensate for different lighting conditions...
logic-to-light deviceA fiber optic component or system designed in such a way that it can be operated by people without specialized knowledge of...
calcite interference microscopeA microscope that allows examination of a small crystal and conveniently provides linearly polarized object and reference...
rare-earth elementsRare-earth elements (REEs) are a group of seventeen chemical elements found in the Earth's crust, characterized by their...
cold-light illuminationA means of illumination from which the infrared component has been removed by absorption or reflection filters within the...
photonic crystalsPhotonic crystals are artificial structures or materials designed to manipulate and control the flow of light in a manner...
photon correlation spectroscopySpectroscopy used to study the concentration, diffusion and Brownian motion of small particles suspended in a fluid by...
quantum efficiencyQuantum efficiency (QE) is a measure of the effectiveness with which a device or system, typically in the context of...
Abney effectThe alteration and reduction of color with the addition of white light. The perceived color shift that occurs as the...
temporal responseCharacteristic of deflected light power defined as the quadratic invariant function of the video signal amplitude.
antiguideA waveguide that has a core with a lower refractive index than the refractive index of the cladding. This structure can...
optical systemA group of lenses, or any combination of lenses, mirrors and prisms, so constructed as to refract or reflect light to...
second-order nonlinear optical propertiesSecond-order nonlinear optical properties refer to a class of phenomena exhibited by certain materials in response to...
laser paintingExtended period exposure photographs of a laser light created with various patterns within full image (laser graffiti).
lumenA lumen is a unit of measurement used to quantify the amount of luminous flux, which is the perceived power of light. In...
light adaptationThe ability of the human eye to adjust itself to an alteration in the intensity of light.
penumbraA source of light will not cast a distinct shadow of an interfering, opaque object, but will cast a shadow having two parts:...
zirconium arcA small bulb containing a conducting gas, an arc being formed between a metal ring and a tiny zirconium electrode near the...
epitaxial equipmentEpitaxial equipment refers to a set of specialized tools and systems used in the process of epitaxy, which is the growth of...
infraredInfrared (IR) refers to the region of the electromagnetic spectrum with wavelengths longer than those of visible light, but...
optical activityThe capacity of a chiral substance such as a crystal or molecule to rotate the plane of polarized light that is transmitted...
prismA prism is a geometric optical element with flat, polished surfaces that refract light. It is typically a solid, transparent...
electron multiplication charge-coupled device cameraAn EMCCD (electron-multiplying charge-coupled device) camera is a type of scientific camera specifically designed for...
image converter high-speed cameraA camera that uses an image converter tube in such a way that voltage waveforms applied to internal electrodes cause the...
stroboscopic light sourceAn electronic flash tube capable of repeated operation at hundreds or thousands of flashes per second for long periods.
etalonAn etalon is an optical device that consists of two parallel reflecting surfaces separated by a precise and known distance....
axial colorA lens aberration that causes axial light rays having different wavelengths to focus at various points along the axis.
concave gratingA reflecting grating ruled on a concave spherical surface that not only disperses the light but focuses the spectrum. The...
polarizing filterA filter that polarizes light passing through it. It is possible to fabricate sheets of plastic or gelatin that contain...
intensified charge-coupled deviceA CCD image sensor that uses a proximity-focused image intensifier to provide greater sensitivity at low light levels.
diverging lensA diverging lens is a type of lens that causes parallel rays of light to spread out or diverge. It is thinner in the center...
edge-emitting LEDAn edge-emitting light-emitting diode is a type of LED structure where light emission occurs primarily along the edge of the...
optical emission spectroscopyIn dry etching, a method of characterizing the composition of solid materials such as metal. Atoms in the OES technique are...
optical gateAn optical gate typically refers to a device or system that controls the transmission of light, allowing it to pass through...
stroboscopeA device that produces brief flashes of light for observing the behavior of an object during a short interval. One of the...
antireflection coatingAn antireflection coating (AR coating) is a thin film or coating applied to optical surfaces, such as lenses or windows, to...
ultraviolet fiber opticsUltraviolet (UV) fiber optics refers to optical fibers that are designed and optimized for the transmission of ultraviolet...
photodarkeningThe effect that the optical losses in a medium can grow when the medium is irradiated with light at certain wavelengths.
photochromicPhotochromic refers to a property exhibited by certain materials, typically organic compounds or dyes, which undergo...
launch angleThe angle between the light input propagation vector and the optical axis of an optical fiber or fiber bundle.
sensitometerAn instrument for determining the sensitivity of a photographic film to light. The film is given either a stepped exposure...
sine wave targetBar pattern represented as a sine curve in which the light distribution varies in one direction.
spectroscopySpectroscopy is a technique used in the study of interactions between matter and electromagnetic radiation. It involves...
lensometerAn ophthalmic instrument used to measure the magnitude and direction of the maximum and minimum powers of a spectacle lens,...
light negativeThat property of a substance that determines that there will be a decrease in conductivity when exposed to light radiation.
Savart plateA double-plate device used to transmit polarized light and form interference fringes of the light, thus indicating its...
medical lasersMedical lasers are devices that produce intense beams of light with specific characteristics and properties, which are used...
plasma shieldPlasma's ability to stop the transmission of laser light.
scintillation detectorA scintillation detector is a radiation detection device that utilizes scintillation crystals to detect and measure ionizing...
latticeIn photonics, a lattice refers to a periodic arrangement of optical elements or structures, often on a microscopic or...
optical isolatorAlso known as an optical diode, an optical isolator is a device that utilizes the Faraday effect to suppress or redirect...
color visionAspect of vision permitting the observer to distinguish among stimuli by their hue, saturation, and brightness or lightness.
achromatic prismCemented prisms of differing refractive indices which refract incident light and, due to differing refractive indices, will...
allochromyAny fluorescence in which the wavelength of the emitted light differs from that of the absorbed light.
diffusion (light)
optical correlatorA device incorporating a spatial light modulator and a reference filter; used for matching an input optical waveform or...
near-field scanning optical microscopeA scanning probe microscope that analyzes the surface of a specimen by recording the intensity of light as it is focused...
amplitude (light)The magnitude of the electric vector of a wave of light. See electric vector; magnetic vector.
epifluorescence microscopyFluorescence imaging technique in which the excitation light from the objective is directed into the sample producing...
Fizeau fringesFizeau fringes are interference fringes observed in an interferometer, specifically in a Fizeau interferometer. The Fizeau...
differential absorption lidarA lidar (light detection and ranging) technique used in pollution monitoring. Two light beams are emitted simultaneously,...
transverse field modulatorA Pockels cell in which electrical current is applied in a direction orthogonally to that of the light beam.
Abbe illuminationImage of a uniform source through the sample of a microscope image system. Light from the sample plane is reimaged by the...
photoelectric scannerA system mounted a few inches above a moving plane that consists of a light source, lenses and one or more phototubes. In...
emission spectrumAn emission spectrum is a graphical representation or a characteristic pattern of the wavelengths or frequencies of light...
light-activated silicon-controlled switchSimilar to LASCR, except that all four regions are available.
q-switched operationQ-switched operation, or q-switching, is a technique used in lasers to produce short and intense pulses of light. The term...
pupil1. In the eye, the opening in the iris that permits light to pass and be focused on the retina. 2. In a lens, the image of...
photoemissive detectorAn electronic tube instrument in which the anode current varies with the intensity of light incident on the cathode.
side-lit cableA type of fiber optic cable that emits light from its sides along its length.
scientific complementary metal-oxide semiconductorScientific complementary metal-oxide semiconductor (sCMOS) refers to a type of image sensor technology specifically designed...
silicon photodiodeA silicon photodiode is a semiconductor device that converts light into an electrical current. It is a type of photodetector...
total internal reflectionThe reflection that occurs within a substance because the angle of incidence of light striking the boundary surface is in...
calibrated light sourceA lamp whose output can be traced to a standard light source.
optical combinerAn optical combiner, in the context of optics and display technologies, refers to a device or component that combines...
magneto-opticsMagneto-optics refers to the study and manipulation of the interaction between magnetic fields and light (electromagnetic...
optical densityA measure of the transmittance through an optical medium. Optical density equals the log to the base 10 of the reciprocal of...
linear arrayA solid-state video detector consisting of a single row of light-sensitive semiconductor devices, used in linear-array...
fiber Bragg gratingA fiber Bragg grating (FBG) is a type of optical filter that is inscribed or "written" into the core of an optical fiber. It...
superresolutionSuperresolution refers to the enhancement or improvement of the spatial resolution beyond the conventional limits imposed by...
bench photometerA device used to compare the luminous intensities of two sources by locating a point between the two light sources where the...
reflective spectroscopyReflectance spectroscopy is a technique used to analyze the reflective properties of materials across various wavelengths of...
intensity-modulated sensorA type of fiber optic sensor that responds to a change in the intensity of received light caused by the displacement or...
direct-vision pocket spectroscopeA small handheld instrument consisting of a slit and collimator that feeds light into a small direct-vision dispersing...
aplanatic surfaceAn aplanatic surface is an optical surface that is specifically designed or shaped to minimize spherical aberration and...
anisophotic sourceA light source that emits an uneven distribution of radiant energy through the visible range.
mirrorA smooth, highly polished surface, for reflecting light, that may be plane or curved if wanting to focus and or magnify the...
liquid crystal on siliconLiquid crystal on silicon (LCoS) is a display technology that combines liquid crystal materials with silicon-based...
quasi-monochromatic lightSingle wavelength source with a larger linewidth often containing multiple longitudinal modes.
light pipeTransparent matter that usually is drawn into a cylindrical, pyramidical or conical shape through which light is channeled...
multianode microchannel array detectorA photon-counting instrument for use in both space-borne and ground-based photometric and spectroscopic instrumentation....
optical theoremA fundamental law of wave scattering theory that connects the extinction cross section of a scatterer to the real part of...
optical spectrum1.) Generally, the electromagnetic spectrum within the wavelength region extending from the vacuum ultraviolet at 40 nm to...
acoustical holographyThe optical reconstruction of image information contained in a sound field. First the diffraction pattern, formed by an...
coudéA set of mirrors along a telescope's polar axis designed to redirect light to a fixed position without being affected by the...
optical time-domain reflectometryA method for characterizing a fiber wherein an optical pulse is transmitted through the fiber, and the resulting light...
photopolymerizationA process in which a mixture of one or more monomers, plus a catalyst, polymerize under exposure to light radiation....
beam matrix1. A geometrical arrangement of two or more light beams for use in laser shows, object detection or other applications...
phase maskIn optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it....
electrocapillarity modulatorA type of optical modulator with potential application in optical switching and displays, in which applied voltage causes a...
Brewster angle windowA parallel plate of glass in such a position that the refracted and reflected rays of incident parallel light are mutually...
galvanometer mirrorA small mirror, sometimes plane and sometimes concave, attached to the rotating coil of a galvanometer to cause a spot of...
photosensitivityThat property of a material indicating that it will react when exposed to light energy.
optical profilerAlso known as a white-light interferometer. Measures surface texture and shape from nanometer-scale roughness to...
flicker photometerA bench photometer that depends on the inability of the eye to distinguish color in brief flashes of light. Any difference...
dynamic magneto-optical correlatorAn optical correlator incorporating a binary phase-only spatial light modulator made from an iron garnet magneto-optic solid...
coherent fiber bundleA coherent fiber bundle (CFB), also known as a coherent fiber optic bundle, is an assembly of multiple optical fibers...
electric dichroism spectroscopyThe use of a krypton laser system for the measurement of small molecules aligned by an electric field, by analyzing the...
flash spectroscopyThe study and interpretation of the spectra of substances after they have absorbed the radiant energy emitted by a brief,...
photon jetA photon jet is a narrow, highly collimated beam of light that is formed when light interacts with small dielectric...
low-loss fiberOptical fiber that transmits a greater percentage of input light than does high-loss step-index fiber. Low-loss fiber...
microlithographyA technique for producing micron-size structures on surfaces by using short-wavelength light or electron beams.
microheterogeneous systemsExtremely small organic and inorganic systems of molecules within a substance. In general, systems are colloidal size in...
hyperspectral imagingHyperspectral imaging is an advanced imaging technique that captures and processes information from across the...
liquid core optical fiberMultimode straight fiber capable of transporting linearly polarized light with any incident polarization angle, and in which...
optical barcode readerAn optical barcode reader, commonly known as a barcode scanner, is a device that uses optical technology to capture and...
bacteriorhodopsinA light-harvesting protein found in the purple membrane of a micro-organism called Halobacterium halobium. The protein...
multiple wavelength interferometryA specific form of phase shifting interferometry - commonly referred to as multiple wavelength phase shifting interferometry...
solid-state imaging systemAn imaging system that uses a mosaic of tiny light-sensitive semiconductors (phototransistors) to produce individual outputs...
CCD cameraA CCD camera, or charge-coupled device camera, is a type of digital camera that utilizes a CCD image sensor to capture and...
photoelectric receiverAn instrument that uses a photocell to detect and measure the intensity of incident light.
phase-contrast microscopeA microscope that has an annular stop in the lower focal plane of the condenser, and a quarter-wave retarding and absorbing...
photoluminescenceThe state of optically excited luminescence. Luminescence refers to the light emitted by excited atoms or ions as they decay...
scanning spectroradiometerA spectroradiometer having a means to scan different regions of the light spectrum, providing simultaneous representations...
conjugate pointsThe two points on the principal axis of a mirror or lens so positioned that light emitted from either point will be focused...
macula luteaThe small central portion of the human retina that is responsible for providing the clearest, and most distinct aspects of...
lens blankA lens blank is a piece of optical material in a raw, unfinished state, typically in the form of a disk or block, from which...
reflection reduction coatingThe thin, transparent film made up of specific substances applied to glass-air surfaces for the purpose of decreasing the...
laser rangefinderA laser rangefinder is a device that uses laser technology to measure the distance between the device and a target. It...
magneto-optic storageA specific type of storage in which the material to be written on is heated above its transition temperature and switched in...
spectral repeatabilitySpectral repeatability refers to the consistency and reproducibility of spectral measurements across multiple trials or...
retina cameraA special-purpose camera used by ophthalmologists to photograph the retina of the eye. The optical system operates through...
photolithographyPhotolithography is a key process in the manufacturing of semiconductor devices, integrated circuits, and...
multi-axis alignmentMulti-axis alignment refers to the process of aligning or adjusting components or systems in multiple spatial dimensions or...
active-matrixAn OLED display that has an integrated electronic backplane as its substrate. Active-matrix OLED displays use at least two...
thin-film solar cellA solar cell that is lightweight and flexible because of its construction by vacuum deposition of a semiconductor material...
photodiode detectorA photodiode detector is a semiconductor device that converts light into an electrical current. It operates based on the...
photodynamic inactivationPhotodynamic inactivation (PDI) is a therapeutic approach that utilizes the combination of light, a photosensitizer, and...
comparison lampA reference incandescent light source having a luminous intensity that is used in photometry for comparison of other light...
ellipsometryEllipsometry is an optical technique used to characterize the properties of thin films and surfaces. It is based on the...
fluorometryThe analysis and measurement of the fluorescence emitted by a source. Fluorometric processes are more sensitive than light...
absolute purity thresholdLeast value of color value combinations which gives white light; minimum purity as determined to be white.
photosphereThe apparent surface of the sun or a star from which light appears to radiate.
triangulationA method of measuring distance by recording a single scene from two points of perspective. Surveying instruments can be...
excitation1. The process by which an atom acquires energy sufficient to raise it to a quantum state higher than its ground state. 2....
volumetric imagingVolumetric imaging refers to the capture, visualization, and analysis of three-dimensional (3D) information from a volume of...
optical bottleA term referring to an optical force field used to trap and stabilize particles acted upon by a force such as laser light.
fluorescence microscopyFluorescence microscopy is a specialized optical imaging technique used in biology, chemistry, and materials science to...
threshold voltage1. Voltage at which a PN junction begins to pass a current. 2. In a solid-state lamp, the voltage at which light is first...
laser photochemistryThe study concerned with the stimulation of chemical activity by laser light as a result of the absorption of photons by a...
excimer laserAn excimer laser is a type of ultraviolet laser that emits short pulses of light in the ultraviolet spectrum. The term...
principal sectionA plane passing through a crystal that has the optic axis of the crystal and the light ray under consideration.
fiber optic imaging bundleA fiber optic imaging bundle is a specialized optical device composed of multiple optical fibers bundled together. Each...
colorimetric purityRatio, to the luminance of a test color, of the luminance of the spectrum color that matches the test color when mixed with...
lateral waveLight generated along the interface when light is incident in the neighborhood of the total internal reflection angle.
jellet prismA prism produced by severing a Nicol prism and reconstructing the polarization angles of the two halves so that they are...
time-to-amplitude converterA time-to-amplitude converter (TAC) is an electronic circuit that converts a time interval between two events into an...
3D laser line profile sensorA 3D profile sensor, also known as a 3D profiling sensor or 3D depth sensor, is a technology that is used to capture and...
residual blueThe optical phenomenon in which white light dispersed by small particles in suspension appears blue when viewed through a...
evanescent field theoryA high-frequency approach to the propagation of light in graded-index fibers in which the modal field is represented in...
negative ghostA ghost image that has the reverse lightness relations of the original image. This phenomenon is a common optical illusion...
beamwidthThe angular width of a radiation beam. With respect to a conical beam of light, it is the vertex angle of the cone. The...
x-ray opticsThe study of the physics of x-rays, where the x-rays exhibit properties similar to those of lightwaves. Also called Roentgen...
freeform mirrorsFreeform mirrors refer to reflective optical components that deviate from traditional symmetric or rotationally symmetric...
heterochromatic lightRadiation consisting of more than a single wavelength in the visible region of the spectrum.
retarder cellA device that uses nematic liquid crystals sandwiched between fused silica substrates to change the phase of polarized...
anomalous dispersionDispersion that occurs when the medium's index of refraction decreases as the frequency of the propagating light increases....
local injection detection systemA device used to evaluate the quality of fiber optic splices made in the field by injecting light into the cladding of the...
concave and convex spherical mirrorConcave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These...
isophoteA curve or surface having equivalent light intensity.
chalniconProprietary name for a low-light-level TV pickup tube.
long-pass filterA long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or...
light chopping
additive color processA process of color photography in which colors are added one to another in the form of light, rather than as colorants, to...
opacityA measure of a material's inability to transmit light, equal to the reciprocal of its transmittance.
beaconA device, either visual or electronic, that emits signals to identify set positions for use in the navigation of aircraft...
excimer laser coronary angioplastyExcimer laser coronary angioplasty (ELCA) refers to a medical procedure used in the treatment of coronary artery disease....
2D profile sensorA 2D profile sensor is a type of sensor used in various industrial and technological applications to measure and capture...
photoelectric photometerAlso known as electronic photometer. A photometer with a photocell, phototransistor or phototube for measuring the intensity...
fluorochromeThe combination of the organic dye in a stained specimen and the antibodies produced that is detected by exposure to light.
near-ultraviolet light sourceA light source, such as the sun or an incandescent lamp, that freely penetrates ordinary glass bulbs and emits in the...
dispersionDispersion refers to the phenomenon where different wavelengths (colors) of light travel at different speeds when passing...
critical flicker frequencyRelative to a light source, the frequency at which the source appears to fluctuate in light intensity half the time and...
acceptance angleThe range of angle or solid angle values by which light may enter an optical system.
emulsion speedThe sensitivity of a photographic emulsion when exposed to light, provided that the film is developed through a standard...
source correlationThe relationship between different wavelengths of light generated by a source, which may affect the spectral distribution of...
safelightFiltered light to which photographic or other photosensitive materials are not responsive; used to illuminate darkrooms when...
photonA quantum of electromagnetic energy of a single mode; i.e., a single wavelength, direction and polarization. As a unit of...
light balancing filter
laserA laser, which stands for "light amplification by stimulated emission of radiation," is a device that produces coherent and...
photoacoustic calorimetryPeriodic interruptions of a light beam incident on an absorbing medium that produce heat, expansion and acoustic wave...
pixel binningPixel binning, also known as pixel merging or pixel combining, is a technique used in digital imaging and camera technology....
Pockels cellA Pockels cell, also known as an electro-optic modulator, is an optical device used to control the polarization of light by...
bias buildupDegradation factor in coherent light systems where the amplitude of the recorded signal is decreased as the number of object...
indiumMetal used in components of the crystalline semiconductor alloys indium gallium arsenide (InGaAs), indium gallium arsenide...
sapphireSapphire refers to a crystalline form of aluminum oxide (Al2O3) that is used in various optical and photonic applications...
radial astigmatismThe astigmatism in a lens system that results when light enters the system at an oblique angle.
normalSometimes referred to as the surface normal or 'surface norm'; the normal is an axis that forms right angles with a surface...
equal-energy sourceA light source that produces an equal-energy spectrum.
picosecond spectroscopyA method of measuring complex sequential photosynthetic reactions by varying the pulse time and wavelength of light...
bending of light1. That action occurring when light passes through an optical interface at other than normal incidence, i.e., refraction. 2....
holographyHolography is a technique used to capture and reconstruct three-dimensional images using the principles of interference and...
excitation potentialThe amount of energy required to raise the energy level of an atom; a necessity if the atom is to radiate energy. High...
reflecting prismA prism having several plane polished surfaces, some to transmit light, some to reflect light, and some to serve both...
diascope1. An optical device used for projection of enlarged images of transparencies or lantern slides on a screen. 2. A device...
coherent light sourceA light source that is capable of producing radiation with waves vibrating in phase. The laser is an example of a coherent...
delay timeThe interval between direction of signal to a light-emitting diode and attainment of 10 percent output current in the...
dark frameA frame taken to identify electronic noise in a CCD imaging device. A dark frame is recorded without exposing the CCD to any...
absorption peakAn absorption peak refers to a sharp increase or spike in the absorption of electromagnetic radiation at a particular...
primary colorsA set of three colored lights which, when mixed, give the sensation of white light. The set used in color television, for...
optically pumped laserA laser in which stimulated emission is triggered by the absorption by electrons of light from an auxiliary source such as a...
stimulated Brillouin scatteringIn Stimulated Brillouin Scattering (SBS), an incident photon (usually laser light) interacts with acoustic phonons in a...
spectrographAn optical instrument for forming the spectrum of a light source and recording it on a film. The dispersing medium may be a...
reliefThe discernment of depth or apparent difference in distance that causes the object to stand out from its background because...
phaseIn optics and photonics, "phase" refers to a property of electromagnetic waves, such as light, that describes the position...
extreme ultravioletExtreme ultraviolet (EUV) refers to a specific range of electromagnetic radiation in the ultraviolet part of the spectrum....
gallium aluminum arsenideA crystalline semiconductor alloy used as the light confinement layer in both single- and double-heterostructure diode...
veiling glareDiffuse stray light at the image plane of an optical system that results in reduced contrast and resolution.
catoptric lightLight that is directed or focused by means of curved reflective surfaces.
stabilized light sourceA light source that does not fluctuate despite temperature changes.
fiber optic gyroscopeA fiber optic gyroscope (FOG) is a type of gyroscope that uses the interference of light waves to detect changes in...
machine vision systemA machine vision system is an integrated combination of hardware and software components designed to capture, process, and...
spectral order (diffraction grating)When, for example, a beam of monochromatic light passes through a diffraction grating, the emergent rays that have remained...
Fabry-Perot fringesThe series of rings when monochromatic light passes through a Fabry-Perot interferometer.
chromaticnessThe sensations of hue and saturation, taken together, but not brightness or lightness.
optical pyrometerAn instrument for determining the temperature of a hot object by examining the color spectrum of the visible light it gives...
lens transmissionThe ratio of the intensities of a light bundle before and after passing through the lens.
index of refractionThe ratio of the velocity of light in a vacuum to the velocity of light in a refractive material for a given wavelength.
otoscopeAn otoscope is a medical device used by healthcare professionals, particularly ear, nose, and throat (ENT) specialists,...
acousto-optic modulators and deflectorsAn acousto-optic modulator (AOM) is a device that utilizes the interaction between sound waves and light waves to modulate...
convexConvex is an adjective used to describe a surface or shape that curves outward, bulges, or has a rounded and outwardly...
light rayThe path of a given point on a wavefront. One of the radii of a wave of light that indicates the direction of light travel.
scintillation phosphorA phosphor that has the ability to convert into light emission a portion of energy lost by ionization when a charged...
Raman spectroscopyRaman spectroscopy is a technique used in analytical chemistry and physics to study vibrational, rotational, and other...
hyperspectral resolutionHyperspectral resolution refers to the level of detail or granularity in the spectral information captured by a...
scanning line1. The continuous thin strip marked by the scanning beam. Generally, during return of the scan, the line is blanked out. 2....
base-altitude ratioIn aerial photography, the ratio derived from a stereoscopic pair of photographs that represents the air-base length divided...
Photoelastic equipment and suppliesPhotoelastic equipment and supplies refer to instruments and materials used in photoelasticity, a technique used to analyze...
photoelectric photometryThe use of photoelectric sensors to detect and measure the intensity of a light source. This application, as compared to...
halftonesThe gray-colored tones halfway between shadows and highlights in a reproduced image.
multichannel spectral analyzerA spectrometric instrument that detects radiation simultaneously in multiple channels, sorts it spectrally from the deep...
tourmalineA naturally occurring crystalline mineral that has the property of polarizing transmitted light. It is little used now that...
APD detectorAn APD detector, or avalanche photodiode detector, is a type of photodetector used to detect light or optical signals by...
deformable mirror deviceA spatial light modulator consisting of a metallized polymer film stretched over an array of metal-oxide semiconductor...
fluorescence decay systemA device, also called a fluorescence lifetime instrument, that measures decay curves of fluorescing samples. It generally...
wedgeAn optical element having plane-inclined surfaces. Usually the faces are inclined toward one another at very small angles....
image intensifierAn image intensifier, also known as an image intensification tube or image intensification device, is a specialized...
ultrasonic light diffractionThe optical diffraction spectra formed, or the method that produces them, when a light beam is transmitted through a...
Ultraviolet-CUltraviolet-C (UV-C) refers to a specific range of ultraviolet radiation with shorter wavelengths than those of visible...
image enhancing equipmentComplex devices, often involving a computer, in which a photograph is scanned by a point of light, the amplitude of the...
direct laser interference patterningAlso called DLIP, a high-speed, high-resolution processing technique that uses high-power, pulsed laser systems to directly...
right-angle prismA type of 45-90-45° prism used to bend a beam of light through a right angle with the surfaces forming the 90° angle...
arc light sourceIn present usage, especially for spectroscopic identification, an arc between electrodes that serves as a radiation source....
total internal reflection fluorescenceTotal internal reflection fluorescence (TIRF) microscopy is an advanced fluorescence microscopy technique that leverages the...
laser contact tipA surgical device used to deliver laser light. Specifically,contact tips are made with artificially grown sapphire which is...
indirect illuminationThe light formed by visible radiation that, in traveling from light source to object, undergoes one or more reflections. In...
dispersion-shifted fiberA dispersion-shifted fiber (DSF) refers to a type of optical fiber designed to minimize the effects of chromatic dispersion,...
electromagnetic spectrumThe total range of wavelengths, extending from the shortest to the longest wavelength or conversely, that can be generated...
Callier coefficientThe coefficient termed by Callier as the ratio between the density of photographic negatives measured by parallel light and...
fiber optic lightguideA bundle of optical fibers arranged randomly for the purpose of transmitting energy, not an image.
sodium light sourceAn electric discharge lamp in which the conducting vapor is that of metallic sodium instead of the usual mercury. It emits a...
solar simulatorA solar simulator is a device used to replicate the spectrum and intensity of sunlight in a controlled environment for...
lamp housingA device designed to concentrate and direct a light source by enclosing the source in it and using a concave reflector to...
phototelegraphyA document-transmitting process that uses a cylinder that rotates the document to be scanned and detected by a photoelectric...
chromatic aberrationChromatic aberration is an optical phenomenon that occurs when different wavelengths (colors) of light are refracted by a...
photochromatic compoundA chemical compound that exhibits a reversible change in its absorption spectrum upon irradiation with given wavelengths of...
Raman fiber probeA flexible fiber cable with a small diameter that transports light from the excitation laser to the target. Used in Raman...
supercontinuumSupercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the...
laser coolingA process and method by which manipulation and orientation of a given number of directed laser beams decreases the motion of...
nanostructured glassA unique glass made up of nano-structured materials to create millimeter sized monolithic glass space-variant polarization...
xenon arc photocoagulatorAn instrument for eye surgery that directs intense xenon arc light through the transparent cornea lens to the retina where...
optical continuous wave reflectometerAn instrument used to measure backscatter as well as optical return loss and reflectance within an optical fiber system by...
temporal coherenceA characteristic of laser output, calculated by dividing the speed of light by the linewidth of the laser beam. The temporal...
nematic phaseA form of liquid crystal with an appearance of moving, threadlike structures, particularly visible when observed in thick...
grapheneGraphene is a two-dimensional allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal...
rare earth dopantsRare earth dopants refer to elements from the lanthanide series, also known as rare earth elements, that are intentionally...
aspheric lensAn aspheric lens is a type of lens whose surface profiles deviate from the traditional spherical shape. Unlike spherical...
darkroomA room that is light-tight, permitting total darkness or illumination with a safelight when working with photosensitive...
backlightingThe forming of a clear silhouette of an object by placing a light source behind it. Used in machine vision when surface...
quick-flashing light
gegenschein-zodiacal light photometerA photometer used to measure sky brightness and polarization associated with zodiacal light, background starlight, F-region...
cross dispersionRecombination of only the light that is correctly dispersed by the first stage of a polychromator through its wide...
metalensA metalens, short for "metasurface lens," is a type of optical lens that uses nanostructured materials to manipulate light...
Gaussian beamA beam of light whose electrical field amplitude distribution is Gaussian. When such a beam is circular in cross section,...
Lorentz oscillator modelThe Lorentz oscillator model is a theoretical model used in physics to describe the response of a charged particle (such as...
retroreflectionRetroreflection is a phenomenon in optics where light is reflected back toward its source, typically in a direction nearly...
lambertian surfaceA perfectly diffusing surface; the intensity of the light emanating in a given direction from any small surface component is...
spectrophotometerA spectrophotometer is a scientific instrument used to measure the intensity of light at various wavelengths in the...
photoacoustic effectGeneration of an acoustical signal by a sample exposed to modulated light.
Taylor criterionStates that in interferometers in which the separation of the maxima is equal to the half-value width, a slight drop in...
light modulatorA device that is designed to modulate a beam of light, usually from a laser source, by acting upon the beam directly. The...
color centerA color center, in the context of materials science and condensed matter physics, refers to a specific type of...
circular birefringenceThe optical phenomenon in which right circularly polarized light transmitted by an active medium travels at a different...
flash photolysisA spectroscopic technique used in the detection of free radicals by virtue of their electronic spectra. In this method, an...
echelle gratingA specialized form of diffraction grating consisting of assembled glass plates of equal thickness that resemble a flight of...
luminous fluxDescriptive of the radiant power of visible light modified by the eye response. It is the measure of the flow of visible...
phase matchingPhase matching is a crucial concept in the field of optics, particularly in nonlinear optics and the generation of coherent...
hologonA multifaceted holographic disc that is rotated by a motor to deflect incident light to a scanning system's lens.
photodetectorA photodetector, also known as a photosensor or photodiode, is a device that detects and converts light into an electrical...
adaptive opticsAdaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of...
CIE sourceStandard light source representative of the quality of specified natural or artificial illumination.
motion picture cameraA camera equipped with a lens and a long length of perforated film, the latter being moved intermittently between exposures...
illuminationThe general term for the application of light to a subject. It should not be used in place of the specific quantity...
microflashAn extremely short, high intensity electronic flash of light, having a duration of about 1 x 10-6 s, used in photographing...
electron lensAn electric field produced to influence an electron stream much in the same manner that a lens affects a light beam.
colorimetric photometerA photometer that uses a set of color filters to measure the intensity of light in various regions of the spectrum.
light amplifierA device that serves to emit light of the same wavelength as the input light, only with an increase in intensity. It may be...
atmospheric opticsThe analysis of the properties of radiation, such as light, when acted upon by variations in the atmosphere. Blue and red...
fresnelA unit of frequency equivalent to 1012 cps. Named for Augustin Jean Fresnel, a French physicist known for his work in light...
inertial fusion energyInertial fusion energy (IFE) refers to a proposed method of generating electricity by harnessing the energy released from...
light frameThe term for an image captured by a detector and from which a dark frame, bias frame and/or flat-field frame can be...
near-infrared spectroscopyNear-infrared spectroscopy (NIRS) is a non-invasive analytical technique that uses the near-infrared region of the...
electrowetting displayAn electrowetting display (EWD) is a type of electronic display technology that utilizes the principles of electrowetting to...
glossProperty of a surface which, because of directional reflection, is responsible for the degree to which reflected highlights...
photoelectric mixingAlso known as light beating. The mixing of two narrowband optical components to produce an AC component in the photocurrent...
scanning beamA light, radar or electron beam used to scan according to a particular method.
light sourceThe generic term applied to all sources of visible radiation from burning matter to ionized vapors and lasers, regardless of...
sonoptographyThe process whereby sound waves are employed to form a three-dimensional image of an object. The process involves generally:...
photoplethysmographyPhotoplethysmography (PPG) is a non-invasive optical technique used to detect changes in blood volume in tissues. It...
optical blackingA light absorbing material applied to ground optical surfaces during the process of making that surface non reflective. Such...
aperture diaphragmThe second adjustable iris diaphragm in an optical system. In the common microscope condenser system, it usually is located...
acousto-optic diffractionLight diffracted by a solid (usually quartz in crystal or fused form) traversed by acoustic waves. If the ultrasonic...
perovskiteThe term perovskite refers to a specific crystal structure commonly found in various materials. Perovskite structures have a...
histochemical stainingHistochemical staining is a laboratory technique used in biology and medicine to visualize specific chemical components...
scattered fringe periodMeasure of the interference fringe pattern produced by the forward scattering of light by an optical fiber; the fringe...
point source lampA lamp, usually incandescent, that has a very compact filament, permitting a greater concentration of emitted light, aided...
birefringenceBirefringence is an optical property of certain materials that causes them to exhibit different refractive indices for light...
microscopeAn instrument consisting essentially of a tube 160 mm long, with an objective lens at the distant end and an eyepiece at the...
positroniumBasically, a hydrogen atom with two alterations, positronium is the lightest atom in the universe and has an extremely light...
Fresnel rhombA type of quarter-wave retarder in the form of a glass rhomb; light entering the retarder undergoes two total internal...
photometricPertaining to the measurement of the intensity of light.
spheric lensA spheric lens, also known as a spherical lens, is a type of optical lens with at least one surface that is part of a...
Brewster's angleFor light incident on a plane boundary between two regions having different refractive indices, the angle of incidence at...
bulk scatteringThe scattering of light within a medium.
wave opticsAlso referred to as physical optics - the area of optics in which the wave nature of light is essential when defining its...
cold atomCold atoms refer to atoms that have been cooled to extremely low temperatures, typically in the microkelvin (µK) to...
barcode scannerAn optical scanning device designed to read information printed in the form of bars of different size by detection and...
optogeneticsA discipline that combines optics and genetics to enable the use of light to stimulate and control cells in living tissue,...
photorefractive materialA material in which the refractive index varies according to changes in the light to which it is exposed. Lithium niobate is...
Twyman-Green interferometerA testing device that provides a contour map of the emergent wavefront for the observer in terms of the given wavelength of...
electric vectorThe electric field associated with an electromagnetic wave and thus with a lightwave. The electric vector specifies the...
N, nA symbol used to represent the refractive index. It is commonly used with a subscript to represent the wavelength of light.
spectrum light sourceA lamp that yields a nonluminous flame; used in the spectroscopic analysis of radiation emitted by a substance placed in the...
phototransistorA solid-state device similar to an ordinary transistor except that incident light on the PN junctions regulates the response...
Lloyd's mirrorA mirror employed with a very high incidence angle to form a pair of coherent light sources by reflection, and therefore...
microwave phototubeA device designed to detect microwave modulation and to mix modulated and unmodulated laser beams. It consists of a...
mirageThe distortion of an object's true image as the result of abnormal atmospheric disturbances along the path traveled by the...
Becquerel effectThe intensification of a latent image, because of exposure to light to which the emulsion is otherwise insensitive.
illuminant metamerismMetamerism that occurs when the light source is changed.
iris diaphragmA mechanical device designed to smoothly vary the effective diameter of a lens, thereby controlling the amount of light...
analyzerAn optical device, such as a Nicol prism, capable of producing plane-polarized light, and used for detecting the effect of...
attosecond photonics sourcesAttosecond photonics sources refer to devices or systems that generate extremely short pulses of light on the order of...
absorption meterA measuring device that uses a light-sensitive cell or detector to determine the amount of light transmitted by a substance.
basic roughnessThe roughness profile shape from which light scattering is expected to occur.
guide factorA factor derived by equating the incident light on the subject to the required incident light for suitable photography. The...
point-focusing collectorA device used in solar systems to direct mirror-reflected sunlight to a heat absorber and heat-driven engine, which turns a...
spectroscopic light sourceA discharge tube filled with various gases and used as a source in spectroscopy.
single-photon-decay spectroscopyA technique for observing the decay of light emissions from sources following their pulsed excitations, based on recording...
crossed prismsThe positioning of two Nicol prisms so that their axes are at right angles to each other. With this arrangement, light...
light-powered telephoneTechnology that relies on a highly efficient photodetector that can detect incoming light signals at one frequency and...
diaphragm shutterA shutter consisting of a ring of interweaving blades that open outward and allow light to pass when they are pivoted at...
photochemistryThe study of chemical reactions stimulated by the properties of light.
structured lightThe projection of a plane or grid pattern of light onto an object. It can be used for the determination of three-dimensional...
kinoform filterA computer-generated kinoform used for data processing because of its use of incoherent light and its wide field of view,...
Winston coneSpecified curved optic intended for maximum collection of light, including off-axis rays, before leaving the exit aperture.
single molecule localization microscopySingle molecule localization microscopy (SMLM) is a group of super-resolution microscopy techniques that surpass the...
tracking1. The process of following an object's movement; accomplished by focusing a radar beam on the reticle of an optical system...
coelostatA plane mirror mounted on a polar axis that lies parallel to the plane of the mirror. When the mirror is rotated once in 48...
streak cameraA high-speed cine camera used to record, on a continuously moving film, very brief events such as a flash of light. The...
mode beatingIn optics, "mode beating" refers to an interference phenomenon that can occur in laser systems with multiple longitudinal...
internet of thingsThe internet of things (IoT) refers to a network of interconnected physical devices, vehicles, appliances, and other objects...
retroreflecting multipass cellTwo lenses, separated by a distance equal to the sum of their focal lengths, and retroreflecting mirror assemblies, one of...
birefringent filterA filter that transmits light in a series of sharp, widely spaced wavelength bands by its sandwich construction of...
light-emitting diodeAn LED, or light emitting diode, is a semiconductor device that emits light when an electric current passes through it. LEDs...
resonance spectrumThe fluorescent emission spectrum emitted by certain substances following the irradiation of one of these substances with...
geometric phase shiftingA technique used to create an achromatic phase shift based on the principle of geometric phase. The phase shift is...
optical coherence tomographyOptical coherence tomography (OCT) is a non-invasive imaging technique used in medical and scientific fields to capture...
spectral domain optical coherence tomographySpectral domain optical coherence tomography is an imaging technique used in medical diagnostics, particularly in...
radial gradientIn gradient index optics, a gradient profile in which the index varies in a direction perpendicular to the optical axis....
selective laser meltingSelective laser melting (SLM) is an additive manufacturing (AM) or 3D printing technology that belongs to the powder bed...
infrared photomicrographyPhotographic recording that uses infrared radiation as the light source to form an image of a microscopic object and a...
slitAn aperture, usually rectangular in shape, with a large length-to-width ratio, and a fixed or adjustable shape through which...
ellipsometerA spectrometer equipped with polarizing prisms and retardation plates that is used in the analysis of elliptically polarized...
doubly refracting crystalA transparent crystalline substance that is anisotropic relative to the velocity of light.
moiré patternThe resulting interference pattern generated from moiré deflectometry, the moiré pattern is a pattern...
diffractionAs a wavefront of light passes by an opaque edge or through an opening, secondary weaker wavefronts are generated,...
ambient lightLight present in the environment around a detecting or interpreting device, especially a machine vision system, and...
surface analysis by laser ionization(SALI) A type of spectroscopy in which neutral atoms or molecules are ionized by an excimer laser beam and then measured by...
landolt bandA dark band that may appear in the field of crossed Nicol prisms with a powerful source such as the sun because the light is...
opal lampA tungsten filament lamp that uses an opal glass bulb to diffuse light.
neutral density filterA light filter that equally decreases the intensity of all wavelengths of light without altering the relative spectral...
corner cubeA corner cube, also known as a corner reflector or retroreflector prism, is a type of optical device used to reflect light...
gradient-index profileThe term gradient-index profile refers to a specific type of refractive index distribution within an optical material. In...
gain-switchingGain-switching is a technique used in lasers to generate short pulses of light by modulating the gain of the laser medium....
Babinet absorption ruleThe rule stating that positive uniaxial crystals have greater absorption with respect to the extraordinary component of...
cardioid condenserAn oil immersion condenser used to permit only light that has been diffracted or dispersed by a microscope specimen to enter...
Goldberg wedgeA neutral-colored gelatin wedge, cast between glass plates, that is used as an intensity scale in certain types of...
Johnson's curveThe graph of a curve describing the spectral irradiance of extraterrestrial sunlight.
isotope shiftThe slight difference in wavelength of an element's given spectral line observed in comparing different isotopes of that...
dispersion filterA complex filter that uses polarization and interference to transmit light that is nearly monochromatic.
double-exposure holographyThe formation of an interferogram by means of two holograms on the same recording medium, often used for determining small...
angle of incidenceThe angle formed between a ray of light striking a surface and the normal to that surface at the point of incidence.
electro-optics1. The branch of physics that deals with the use of electrical energy to create or manipulate light waves, generally by...
Golgi Staining TechniqueThe Golgi staining technique (also called the black reaction) makes it possible to look at the nervous system by rendering...
resonance absorption (light)The re-emission of absorbed energy, having the same wavelength as the incident energy, in an arbitrary direction from a...
attosecond-pump attosecond-probe spectroscopyAttosecond-pump attosecond-probe spectroscopy (APAP) is an advanced technique in ultrafast spectroscopy that allows...
dissonanceIn optics, the production of maxima and minima by the superimposition of two sets of interference fringes from light of two...
photovoltaic cellA photovoltaic cell, commonly known as a solar cell, is a semiconductor device that directly converts light energy into...
laser interferometerAn interferometer that uses a laser as its light source. The purely monochromatic nature of the laser results in improved...
phase-only filterA type of matched filter that responds only to the phase of incoming light; the output has a much greater intensity than...
photosensitive recordingThe recording achieved when a surface, illuminated by a signal-controlled light beam, emits electrons or reacts in some...
particle image velocimetryA whole-flow-field technique providing instantaneous velocity vector measurements in a cross-section of a flow that is...
helium-neon laserA helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates...
beamsplitterA beamsplitter is an optical device for dividing a beam into two or more separate beams. A simple beamsplitter may be a very...
oblique illuminationA common technique in microscopy, oblique illumination is one in which the object is illuminated by a light source that is...
dichroic coatingA dichroic coating, also known as a dichroic filter or dichroic mirror, is an optical coating designed to selectively...
photothermal effectThe cause of some forms of laser injury in which tissue absorbs incident laser light and experiences a damaging rise in...
azimuthal polarizationAzimuthal polarization refers to a specific polarization state of light where the electric field vector of the...
axial gradientIn gradient index optics, a gradient profile in which the refractive index varies along the direction of light propagation,...
computer-generated hologramA computer-generated hologram (CGH) is a holographic image produced using computational methods and algorithms, rather than...
acousto-optic tunable filterA bulk crystalline optic which permits the propagation of light through a volume of index altered material. The variation in...
lumen-secondSI unit of quantity of light.
structural colorStructural color refers to coloration in materials that is not caused by pigments or dyes but is instead a result of the...
xenon flashtubeA high-intensity source of incoherent white light in which a capacitor is discharged through a tube of xenon gas; often used...
enantiomerA molecule that is the mirror image of another molecule. The two mirror-image molecules have the same chemical properties;...
quantum dot light-emitting diodeQuantum dot light-emitting diode (QLED) is a display technology that utilizes quantum dots, which are semiconductor...
four-level laserA solid-state laser consisting of active atoms or ions of a transition metal, rare-earth metal or actinide, imbedded in a...
light-activated silicon-controlled rectifierA PN-PN device with incident light taking the place of gate current; three of the four semiconductor regions are available...
optical chopperA mechanical or electrical-electromagnetic device for periodically interrupting or blocking abeam of light for a brief known...
opticalPertaining to optics and the phenomena of light.
galvanometric scannerA galvanometric scanner, also known as a galvanometer scanner or galvo scanner, is a type of optical scanning device used to...
photopolymer hologramA holographic plate coated by photopolymeric mixtures that are composed of one or more monomers and a photoredox catalyst...
internal surfaceA nonoptical surface, within lenses and lens mounts, that contributes largely to flare by reflecting light into the image...
3D laser triangulation3D Laser Triangulation - A technology that allows sensors to probe the surroundings. Laser triangulation systems have an...
quantitative phase imagingQuantitative phase imaging (QPI) is an advanced imaging technique used in microscopy to measure and analyze the optical...
Förster resonance energy transferFörster resonance energy transfer (FRET) is a mechanism describing the transfer of energy between two closely spaced...
fluoroscopic image intensifierA form of image intensifier designed to amplify a weak fluoroscopic image. The image is received at an input phosphor...
normal dispersionDispersion characterized by an increasing index of refraction in the medium as the frequency of the propagating light...
spatial resolutionSpatial resolution refers to the level of detail or granularity in an image or a spatial dataset. It is a measure of the...
silver halide emulsionAn emulsion in which grains of the photosensitive material silver halide are deposited. Each grain, when exposed to light,...
pencil beamIn astronomy, the main lobe of an antenna pattern that has a small angular extent in two mutually perpendicular directions....
discontinuously reinforced aluminumA composite derived from aluminum alloy powder and silicon carbide, used as an optical substrate in air- and spacecraft...
beam profilerA device that measures the spatial distribution of energy perpendicular to the propagation path of a radiant beam. An energy...
high-gain screenA screen with a reflected or transmitted light beam that is confined to a much smaller bundle than was received by the...
reflectiveThe term reflective is an adjective that describes the ability of a surface or material to reflect light or other forms of...
passive optical componentA device that responds to incident light but does not generate light.
reversion prismA prism made of two elements cemented together that, depending on its orientation, inverts or reverts an image. It may be...
acousto-optic deflectorA system designed with a laser as a light source and a means for producing sound waves extending beyond 100 MHz to deflect...
mass spectroscopeAn instrument that uses electromagnetic fields to sort out the relative masses of atoms and molecules.The same way an...
annular eclipseA type of solar eclipse that occurs when the sun is at perihelion and the moon is at apogee. Because the apparent size of...
electrostatic lensThe electrical distribution that serves to influence an electron beam in the same way that an optical lens affects a light...
Faraday rotationThe effect discovered by Faraday in 1845 whereby nonoptically active materials or substances become capable of rotating the...
Porro prismA 45-90-45° reflecting prism whose surfaces form the 90° angle reflecting the light beam through a total angle of 180°. The...
optical modulatorA multilayered thin-film device used to modulate transmitted light in integrated photonic circuits.
mesopic visionVision at intermediate levels of luminance between photopic and scotopic vision, where both retinal cones and retinal rods...
thermal-infrared cameraA thermal-infrared camera, often referred to simply as a thermal camera, is a type of imaging device that detects infrared...
laser-light-scattering photometerA scattering photometer using scattered light in the solid angle 4.51+0 19° with respect to the forward direction, and...
free-space opticsFree-space optics (FSO), also known as optical wireless communication or optical wireless networking, refers to the...
luminance rangeAn objective measure of an object's brightness that is derived from the ratio of the luminance of its lightest section to...
solar cellA device for converting sunlight into electrical energy, consisting of a sandwich of P-type and N-type semiconducting...
laser plasmaA plasma produced by the interaction of an intense laser pulse with a material surface. Production of ionized particle with...
collimated light
xenon arcThe arc formed when the rare gas xenon is excited electrically and emits a brilliant white light. Xenon is used to fill...
photoelectric currentThe electron stream emitted by a phototube when the cathode is exposed to light.
liquid crystal light valveA liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the...
Mach-Zehnder interferometerA Mach-Zehnder interferometer is an optical device used to measure the phase difference between two collimated beams of...
aperture stopA physical constraint, often a lens retainer, that limits the diameter of the axial light bundle allowed to pass through a...
Bertrand lensA small convergent lens, located between the objective and eyepiece of a microscope, that focuses an image of the upper...
scalar theory of lightThat theory that treats the light field as a single scalar field rather than as two coupled vector fields.
angstromAn angstrom, symbolized by the Ångström or Å, is a unit of length used to express atomic and molecular...
back-illuminated CCDA CCD that has been reduced in thickness by etching so that light passes through the back layers of the CCD. This type of...
coreThe light-conducting portion of an optical fiber, defined by the region of high refractive index.
Wiener experimentAfter putting a thick photographic emulsion on a front-faced mirror, and exposing the emulsion to monochromatic incident...
frequencyWith reference to electromagnetic radiation, the number of crests of waves that pass a fixed point in a given unit of time,...
phase shiftingA technique used to generate a phase shift between reference and sample light beams. The phase shift can be performed...
chemical laserA laser that relies on chemical activity instead of electrical energy to produce the pumping action necessary to form pulses...
optical-grade siliconThe element that resembles a lightweight metal, but when very pure, has a very high electrical resistance and is transparent...
light current
rectilinear propagationStraight line travel. This denotes the fact that light travels in a straight line when traveling through a medium with a...
synthetic interferometric imageAn imaging technique in which an object moving through an interference field formed in space scatters light and is spatially...
gated image tubeAn intensified charge-coupled device that uses a large negative charge at the grid to switch off the flow of electrons at...
thallofide cellA photoconductive cell that uses thallium oxysulfide as the light-sensitive medium.
grating spectrometerA spectrometer that uses a grating to diffract light into specific wavelengths.
Harting Dove prismA direct-vision prism made in one piece that can be used only in parallel light.
red, green, blueRGB stands for red, green, blue, which are the primary colors of light used in additive color mixing. The RGB color model is...
self-phase modulationSelf-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a...
gallium nitrideGallium nitride (GaN) is a compound made up of gallium (Ga) and nitrogen (N). It is a wide-bandgap semiconductor material...
vergenceThe angular relation between two light rays that originated at the same object point. Sometimes used to indicate the angle...
Lyot filterA type of filter consisting of a series of birefringent crystals and polarizers invented by French astronomer Bernard Lyot...
optical coherence tomography angiographyAlso known as OCT-A, optical coherence tomography angiography is an imaging technique that uses light waves to measure...
deep ultravioletDeep ultraviolet (DUV or deep-UV) refers to a specific range of ultraviolet light with shorter wavelengths than those in the...
contrast controlWith respect to television, a potentiometer that allows variation of the intensity of the different elements of an image and...
fluorographic lensA lens having an extremely high aperture and used in the recording of x-ray fluorescent screen images. It often is specially...
low-coherence interference microscopeAn interference microscope that uses a light beam originating from a low-coherence light source. The sample is placed in one...
candlepowerThe luminous intensity of a source of light expressed in candelas.
micro-opticsMicro-optics refers to the design, fabrication, and application of optical components and systems at a microscale level....
Michelson-Morley experimentAn optical experiment carried out conclusively in 1887 that demonstrated that the ether, a hypothetical medium postulated by...
astronomical telescopeAn astronomical telescope is a type of optical instrument designed to gather and magnify light from distant celestial...
colorimeterA colorimeter is a device used to measure and quantify the color characteristics of an object or a light source. It provides...
two-photon excited fluorescenceTwo-photon excited fluorescence (TPEF) is a nonlinear optical method that allows imaging of biological cells and living...
gratingA framework or latticework having an even arrangement of rods, or any other long narrow objects with interstices between...
digital holographic microscopyDigital holographic microscopy (DHM) is an advanced imaging technique that combines holography and digital image processing...
ultrasonic light modulatorAn instrument with a fluid that modulates a light beam traversing it because of the effect of ultrasonic waves passing...
modified chemical vapor depositionModified chemical vapor deposition (MCVD) is a technique used in the fabrication of optical fibers. It is a specialized form...
injection lockingThe use of two lasers as a master-slave pair in order to control frequency and prevent chirp. When light from the master is...
infrared lensAn infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating...
cesium vapor lampA lamp that emits light as the result of the passage of an electrical current through ionized cesium vapor.
illumination distributionGenerally, the orientation of rays of light striking a surface.
spherical microintegrated lensA tiny lens (as small as 100 µm in diameter) used to focus light on charge-coupled devices, formed by heating a...
core-coupled lensA semispherical or conical lens created directly on the core of an optical fiber to focus light from a laser into the fiber...
laser surgeryLaser surgery refers to a medical procedure in which a laser, or focused beam of light, is used as a precision tool to cut,...
alexandriteA host crystal for chromium that emits pulsed or continuous-wave laser light, tunable from about 720 to 790 nm.
polychromatic illuminationLight that is a mixture of wavelengths.
piezo-optical transducerA structure consisting of a thin film of liquid crystal sandwiched between light-polarizing filters that have received a...
dark beamA precision-engineered microminiature light source that is safe for darkroom use, yet emits a beam of light bright enough to...
normal incidenceLight striking a surface at an angle perpendicular to the surface.
clear apertureThe limited light-gathering area of an optical system. The area is normally restricted to an edge or outer surface of an...
blaze wavelengthThe light wavelength for which the direction of reflectance from the groove face is identical to the angle of diffraction...
GaN-based LEDsGallium nitride-based light-emitting diodes (GaN-based LEDs) are semiconductor devices that emit light when an electric...
mode1. The characteristic of how light propagates through a waveguide that can be designated by a radiation pattern in a plane...
bombsightAn instrument that determines, or allows a bombardier to determine, the point in the plane's line of flight at which a bomb...
second-harmonic generationSecond-harmonic generation (SHG) is a nonlinear optical process that occurs when two photons with the same frequency combine...
angle of deviationThe angle through which a ray of light is deviated by a refracting or reflecting surface, or a prism; the angle between an...
YAG crystalA YAG crystal refers to a solid-state crystal made of yttrium aluminum garnet (YAG), which is a synthetic crystalline...
white-light continuumAn extremely wide emission spectrum generated by the nonlinear effects created when a high peak power from a short-pulse...
binocular visionThe ability of the two eyes to see an object from two slightly different points of view. This difference allows an...
concave holographic gratingThe generation of a grating on a concave spherical blank by the holographic process. In this way, ghost images and intense...
strain viewerA viewer that uses the transmittance of polarized light through glass or a similar medium to examine strained regions. See...
light filamentPhenomenon caused by an ultrashort and ultra-intense light pulse propagating in a Kerr medium, such as air or water. When...
geodimeterTrade name referring to an instrument that determines surface distances by measuring the length of time it takes for a...
confocal resonatorA confocal resonator, also known as a confocal cavity or confocal laser resonator, is a type of optical resonator...
remote sensingRemote sensing is a method of data collection and observation where information about objects, areas, or phenomena on...
radio-frequency light sourceA very uncommon lamp in which a tungsten electrode is heated to incandescence by a radio-frequency electrical current.
secondary colorAn aberration that remains after primary color is corrected. Primary color causes the back focus of a lens to vary with...
Sagnac interferometerA type of interferometer in which two coils of optical fiber are arranged so that light from a single source travels...
pyrexTrade name for a type of borosilicate glass manufactured by Corning Glass Works, noted for its low coefficient of thermal...
tomosynthesisA variation of tomography in which several photographs of a patient are taken at different angles, and back-projection of...
aeolightA glow discharge lamp consisting of a cold cathode and a mixture of inert gases. The intensity of illumination varies with...
explosive variableIn cosmology, a star that exhibits a rapid increase in the magnitude of light, which is followed by a slow decrease in...
ultrasonic grating constantThe space between diffracting centers of an ultrasonic wave that is forming certain light diffraction spectra.
multispectral imagingMultispectral imaging is a technique that involves capturing and analyzing images at multiple discrete spectral bands within...
optical parametric oscillatorA laser-pumped crystal with nonlinear optical properties inside of an optical resonator in which the output generates...
luminous paintA mixture of phosphor with a trace of a radioactive element that emits faint light continually. It is used on watch dials...
total fluxThe luminous flux emitted by a light source in all directions.
aluminized cathode-ray tubeA cathode-ray tube having a screen that is coated on the back with a thin film of aluminum, which serves to intensify the...
polarization-insensitive operationCapability requirement for optical switches for transmission lines to process arbitrarily polarized light because of the...
interference colorColor resulting from the interference between two light beams.
phosphorA chemical substance that exhibits fluorescence when excited by ultraviolet radiation, x-rays or an electron beam. The...
bright-field illuminationThe illumination generally used in microscopy, whereby the specimen appears dark against a light background.
Fresnel reflectionFresnel reflection refers to the reflection of light at the interface between two different media with different refractive...
photobleachingPhotobleaching is a phenomenon in which the fluorescence of a fluorophore (a fluorescent molecule or dye) is permanently...
cone1. A solid figure whose base is a circle and whose sides taper upward evenly to a point or apex. Light rays diverging from...
quantum cascade laserA quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics....
optical materialsOptical materials refer to substances or compounds specifically chosen for their optical properties and used in the...
auroraThe strongest light emitted by the Earth's upper atmosphere. It most often can be viewed in the Arctic as the aurora...
Rayleigh prismA prism system designed to produce a very high dispersion of light.
light valveWith respect to display systems, a device that uses an independent light source and a control-layer medium, the active...
synchrotronA synchrotron is a type of particle accelerator that uses magnetic fields to steer charged particles, typically electrons or...
fusion ignitionFusion ignition refers to the point in a controlled nuclear fusion reaction where the energy released by the fusion...
event-based sensorAn event-based image sensor, also known as a dynamic vision sensor (DVS), is a type of digital imaging device designed to...
monochromatic lightLight consisting of a single wavelength or a very narrow band of wavelengths.
transparent electrophotographic filmsImaging materials that generally consist of a polyester base, a transparent electrically conductive layer and an organic...
quasi-opticalHaving properties resembling those of light- waves; e.g., the propagation of waves in the television spectrum.
charge-coupled deviceA charge-coupled device (CCD) is a type of electronic image sensor used in various imaging devices, including digital...
light throughput efficiencyThe fraction of incident light power in an optical modulator that is available to the output beam.
incident light meterAn exposure meter designed to measure the light striking an object and used at a suitable location in a scene.
optical time-domain reflectometerAn optical time-domain reflectometer (OTDR) is a specialized instrument used in optical fiber communications to characterize...
filter factorThe necessary increase of a photograph's exposure time as the result of the additional absorption of light by the filter...
nonlinear optical materialsNonlinear optical materials are substances that exhibit optical properties that are not linearly proportional to the...
calorescenceThe production of visible light by infrared radiation whereby the light is produced by heat and not by any direct change in...
second-harmonic generation microscopyA nonlinear label-free imaging technique commonly used during surgical procedures for the visualization of collagen fibers...
neutral density wedgeA strip or annulus of glass coated with a semitransparent material such as inconel. The coating thickness, and as a result...
image brightnessThe apparent luminance of the image as seen through an optical system. This brightness of the image is determined by the...
immunofluorescenceThe technique that uses light to detect and analyze the antibodies produced by a specimen stained with an organic dye.
Malus's lawA law that uses the square of the cosine between the plane of polarization of a beam of plane-polarized light and the plane...
speckle metrologyRefers to the variety of techniques that use the interference pattern produced by laser light diffusely reflected by an...
wood lensA type of radial gradient lens that can focus light even though its surfaces are flat.
Golay cellA thermal radiation detector consisting of a small cell with a blackened plastic front face that bulges slightly when heat...
extinction meterA type of exposure meter that artificially reduces the light admitted in a sequence of known fractions until a value is...
diffuserAn optical diffuser is an optical component or material designed to scatter or diffuse light that passes through it. It is...
conjugate holographic imageAlso known as real holographic image. The indistinct, highly distorted image produced on the side of the hologram closest to...
backscattering coefficient, bFraction of light counter propagating collinear with the incident source. Processes considering backscattering are Raman,...
optical assemblyAn optical assembly refers to a collection of optical components that are carefully arranged and aligned to perform a...
adaptationSpontaneous changes to the visual system making it more or less sensitive to light.
Becke lineA band of light that appears along the outer edge of a transparent material under microscopic investigation and that moves...
Dammann gratingA Dammann grating is a type of diffractive optical element (DOE) used to create an array of equally spaced,...
optical microphoneLaser-powered telephone device for analog communications that employs a vibrating plastic membrane as a transmitter to...
cyanometerAn instrument designed to measure the proportion of light emitted by a source in the blue region of the spectrum.
grating beamsplitterA grating beamsplitter is an optical device that utilizes the principles of diffraction to split a beam of light into...
mirror mountA mirror mount is a mechanical device used to secure and precisely position mirrors in optical systems. Mirrors are...
fog1. A term used to describe the clouded appearance of an incompletely polished surface that scatters light. 2. The...
compensating glassAlso known as clear glass or clear filter. The clear glass plate is used to simulate a filter, in converging or diverging...
time of flight(TOF) The length of time needed for a signal to arrive at and be reflected from the target. The basis of an active...
monochromatorA monochromator is an optical instrument used to isolate and select a narrow range of wavelengths from a broader spectrum of...
NTSC triangleThe triangle in a chromaticity diagram joining the chromaticities of the NTSC phosphors, and containing all chromaticities...
optical coatingsOptical coatings are thin layers of materials applied to optical components, such as lenses, mirrors, filters, and prisms,...
group indexFor a given mode propagating in a medium of refractive index n, the velocity of light in vacuum c, divided by the group...
astigmatizerA cylindrical lens that may be rotated to distort a bundle of light originating at a point source, to form a line image.
log converterA device designed to convert linear change in the light state at input to log data at output.
double-layer light amplifierA device used to create a light output that exceeds light input, the energy being provided by an electric field. It consists...
paraboloidal mirrorA concave mirror that has the form of a paraboloid of revolution. The paraboloidal mirror may have only a portion of a...
specular reflectionPertaining to the manner in which light is reflected, as by a mirror or speculum.
luminescenceLuminescence is the emission of light that occurs without the involved substance undergoing a significant increase in...
optical noiseOptical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or...
optofluidicsOptofluidics is an interdisciplinary field that combines principles from optics and fluidics to create devices and systems...
phase-change optical discAn erasable data recording and storage medium that uses a laser to heat the crystalline surface of the disc to a certain...
phototheodoliteA camera equipped with angular scales in altitude and azimuth. The scale readings are imprinted on the film when an exposure...
optical air massA measure of the optical path length for light traveling from the sun or other celestial source through Earth's atmosphere...
beam-addressable technologyThe application of reversible writing with a laser beam on particular storage materials. In one method, an amorphous film is...
opaqueA term describing a substance that is impervious to light; the characteristic of a substance that has no luminous...
achromatic pointLocation on the CIE chromaticity diagram which produces the color white for a given light source at a specified temperature.
time delay integrationA method of scanning in which a frame transfer device produces a continuous video image of a moving object by means of a...
rotating hologramA disc composed of a series of holographic optical elements that diffract light at various angles. When spinning, a raster...
native fluorescenceThe light emitted from tissues without the use of fluorescent dyes as markers. Because cancerous tissues and normal tissues...
photonic integrated circuitA photonic integrated circuit (PIC) is a compact and integrated device that incorporates multiple photonic components and...
plane-polarized lightA light beam whose electric vectors all vibrate in a single fixed plane.
Nernst light source
cross sectionCalculation of the probability of an interaction between two types of particles, such as light absorption, excitation or...
etaloningEtaloning is an optical phenomenon that occurs in imaging systems, particularly in devices such as spectrometers,...
optical nonlinearityThe phenomenon that makes nonlinear the mathematical expression for the electrical polarization of a medium through which...
microphotofabricationThe formation of microimages for microreduction. The technique is used, for example, in the production of precision reticles...
phase annulusA term for the ring-shaped stop in a phase contrast microscope. The phase annulus limits the amount of light that reaches...
fiber optic sensorA fiber optic sensor is a device that uses optical fibers to detect and measure physical, chemical, biological, or...
optical distanceThe physical length of the light path in a substance divided by the refractive index of that substance. See also equivalent...
diffuse reflectance spectroscopyDiffuse reflectance spectroscopy (DRS) is a nondestructive analytical technique used to investigate the optical properties...
explosion spectrumThe light spectrum formed by an explosive reaction or by the electrical explosion of a metallic wire by a strong current.
GaAlAs laserA GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic...
narrow-angle dark-field illuminationAn imaging system designed to highlight small deviations in a planar reflective object such as a mirror. The system can be...
silicon carbide light-emitting diodesSilicon carbide (SiC) light-emitting diodes (LEDs) are semiconductor devices that emit light when an electric current is...
Einstein shiftA shift in the direction of the red in the spectral lines of light which, defined by the relativity theory, will have...
blue diode laserA blue diode laser is a type of semiconductor laser that emits light in the blue wavelength range of the electromagnetic...
Er:YAG laserAn Er:YAG laser is a type of solid-state laser that uses a crystal made of erbium-doped yttrium aluminum garnet...
quantum dotsA quantum dot is a nanoscale semiconductor structure, typically composed of materials like cadmium selenide or indium...
endoscopeAn endoscope is a medical device used for visualizing and examining the interior of hollow organs, body cavities, or...
tungsten lampAn evacuated bulb containing a tungsten filament that is heated by passing an electric current through it. In domestic light...
optical leverA device used to detect and measure small amounts of rotation. The rotating object contains a reflecting surface from which...
optical switchingOptical switching refers to the process of controlling the routing or transmission of optical signals within a network using...
destructive interferenceThe interaction of superimposed light from two separate sources that results in a combined intensity that is less than the...
fiber-based confocal luminescence microscopeA microscope in which laser light is delivered through single-mode fibers that replace the pinhole usually used in confocal...
dextrogyrateAble to rotate the plane of polarization of a transmitted, plane-polarized light beam clockwise as seen by a viewer looking...
argon-ion lasergas laser using ionized argon as the active medium and applying electronic excitation in order to produce the laser light
Fresnel lensA Fresnel lens is a type of optical lens that consists of a series of concentric grooves or steps carved into a flat, thin...
luminaireA complete unit containing a light source, globe, reflector, housing, socket and other necessary components for lighting.
grazing incidenceLight striking a surface at an angle almost perpendicular to the normal.
hologramAn interference pattern that is recorded on a high-resolution plate, the two interfering beams formed by a coherent beam...
photogrammetryPhotogrammetry is a technique used to obtain accurate three-dimensional measurements of objects and environments through the...
tristimulus valuesThe values of the three standard or matching stimuli necessary to provide a match with the light under trial, in a specified...
nonperiodic radiationIrregular waves; e.g., light waves, having little coherence and a broad spectrum of frequencies.
bifurcated fiberA branched fiber optic lightguide that performs both receiving and transmitting functions.
corneringThe removal of a slight overlap that may be found on a blank or pressing.
neutral density coatingA coating applied to a neutral density glass that is designed to reduce the amount of light evenly across the transmitted...
surface reflectionAlso known as Fresnel reflection. That portion of the incident radiation that is reflected from the surface of a refractive...
Polarization ImagingA subsurface imaging technique based upon the polarization of light reflected off an object. The polarization of reflected...
gas discharge displayA display device that contains an inert gas that gives off orange light when a high voltage is applied to ionize the gas.
intensity interferometerAn interferometer that functions by first detecting the light striking each aperture and then combining the two detector...
equivalent air pathWhen a block of glass (prism, window, filter, etc.) is placed into a converging light bundle, it increases the physical...
mirror coatingOne or more thin-film layers of optical material deposited on a mirror blank/substrate in order to enhance the way that...
frequency combA frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with...
three-photon microscopyThree-photon microscopy is an advanced imaging technique that belongs to the family of multi-photon microscopy methods. It...
incandescent lampA lamp that emits light when an electric current passes through a resistant metallic wire situated in a vacuum tube.
phosphorescenceLuminescence is the emission of light from a source that is delayed by more than 10-8 s following excitation.
Debye-Sears ultrasonic cellA device used in ultrasonic imaging to measure the velocity and attenuation of compressional waves in a transparent liquid...
back-wall photovoltaic cellA photovoltaic cell designed so that light travels through the front electrode and a semiconductor before it comes to the...
levorotaryCharacterizes a substance whose plane of polarization is rotated counterclockwise as the observer looks through the material...
glassA noncrystalline, inorganic mixture of various metallic oxides fused by heating with glassifiers such as silica, or boric or...
absorption lensAn optical lens manufactured to control the transmission of light over a specified wavelength range. Low absorption lenses...
transparencyAn image affixed to a transparent photographic film or plate by photographic, printing or chemical methods. It may be viewed...
optical path differenceThe relative path difference (or phase shift) traveled between two rays that pass through different mediums from the same...
dark-field discA disc contained within an electronic cell counter for regulating light transmission.
film scanningThe process by which the light from the images of photographic film is encoded into electrical signals for video...
subtractive color processThe basic process of color photography whereby colors are subtracted from white light by means of filters, making all colors...
GaN distributed feedback lasersGaN (gallium nitride) distributed feedback (DFB) lasers refer to a specific type of semiconductor laser based on Gallium...
abrasion markOptical surface damage due to abrasive rubbing. Abrasion damage affects are less than the thickness of the optical coating...
microbubble resonatorA microbubble resonator is a device used in photonics and optical physics for the precise manipulation of light waves. It...
relative indexThe ratio of the velocities of light in two adjacent media, neither of which is air.
arc flashAn arc flash is a sudden release of electrical energy due to an electric arc — a continuous, high-current discharge of...
blaze heightBlaze height typically refers to a parameter in the context of diffraction gratings, which are optical devices consisting of...
gray scalesTransparencies that represent progressive steps in the amount of transmitted radiation for administering predetermined...
wedge photometerA photometer that uses a wedge, marked to show its reduction of flux density, to make two light sources equal in intensity...
mean spherical luminous intensityThe average luminous intensity of a point light source measured over all directions.
RuticonA ruticon is an opto-electronic device in which light going through it can be modulated by an electric field.
The...
machine visionMachine vision, also known as computer vision or computer sight, refers to the technology that enables machines, typically...
integramA reflection hologram using multiple color lasers that integrates various graphical techniques to allow the display of...
optical extentMathematically defined as the product of etendue (or throughput) and the square of the refractive index, the optical extent...
critical scatteringIntense scattering in the region of the liquid-gas critical point. At this point the gas will strongly scatter all light to...
FMCW lidarFMCW lidar stands for frequency-modulated continuous wave lidar. It is a type of lidar (light detection and ranging)...
cladding mode stripperA mechanism or device, especially a coating with a refractive index equal to or slightly greater than that of an optical...
microchannel spatial light modulatorA device to modulate spatially a collimated coherent beam of light with input data in optical data processing. It uses a...
spatial light modulatorA spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of...
electro-optic detectorA device that detects radiation by utilizing the influence of light in forming an electrical signal. It may be a phototube;...
time-correlated single photon countingTime-correlated single photon counting (TCSPC) is a technique used in photon counting applications, particularly in the...
x-ray detectorOne of various types of fluorescent screens used to detect x-ray radiation. Photographic film is mildly sensitive to x-rays,...
Maxwell's equationsThe mathematical set of equations showing the relationship between oscillating electric and magnetic fields that are...
acutanceIn photography, the density gradient across an edge separating light from darkness, a physically measurable quantity that...
reflector lampA lamp used in projection that is made with a reflector built into the bulb, normally by coating a portion of its interior...
gravitational lensThe effect of a powerful gravitational field on light traveling through the field. This effect is detectable in astronomical...
chromosphereA layer between the corona and the photosphere of the sun; its emission is overwhelmed by light emitted by the underlying,...
diffraction angleThe angle that lies between the direction of an incident light beam and any resulting diffracted beam.
flash sensitometerA sensitometer that utilizes an electronic flashtube or a photoflash lamp as both the light source and the shutter for...
contrastThe apparent difference in brightness between light and dark areas of an image. For a light target against a dark...
aerial perspectiveAn optical illusion in which distant objects are lighter in tone and less distinct in outline than those closer to the...
inertial confinement fusionInertial confinement fusion (ICF) is a method of achieving nuclear fusion, a process where two atomic nuclei combine to...
beam attenuatorA device designed to decrease flux density or power per unit area of a light beam through absorption and scattering of the...
MSM photodiodeA metal-semiconductor-metal (MSM) photodiode is a type of photodetector that consists of metal electrodes on a semiconductor...
reflected rayThe light ray leaving a reflecting surface, indicating the path of light after reflection.
concaveConcave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In...
pleochroismThe property exhibited by certain birefringent crystals in which the degree with which they transmit polarized light is...
Verdet constantA factor of an equation of the Faraday effect, which is the rotation of the plane of light polarization by transparent...
brightfieldBrightfield refers to a type of microscopy and imaging technique in which the specimen is illuminated with a white light...
smectic phaseA form of liquid crystal in which flow does not take place in the usual manner. When examined with polarized light, the...
cameraA light-tight box that receives light from an object or scene and focuses it to form an image on a light-sensitive material...
transmission gratingA transparent diffraction grating that serves to transmit light.
Raman shifterA device that changes the frequency of light by inducing the Raman effect on a beam passing through it.
laser oscillatorContains the light or beam path within a laser device. The oscillator uses reflective optical components that are oriented...
contact laser surgeryLaser surgery by means of a low-power laser system using a synthetic sapphire scalpel that transmits the laser light while...
magneto-optic readout deviceA device using the Kerr effect to read back the signals from mechanically recorded tapes and discs. It consists of a light...
autofocus systemA means of adjusting the sharpness of an image automatically, with a sensor for estimating distance or contrast and a drive...
carbon arcAn electric discharge between two carbon rods that are touched together to start the arc and then separated slightly. The...
multileg lightguideA fiber optic bundle split along its length with the ends of the fibers extending separately to illuminate different points...
geometric opticsA field of physics that deals with light as if it truly were composed of rays diverging in various directions from the...
noncoherent bundleAn assembly of optical fibers that will not transmit coherent images or information because the relationship of the fibers...
Smith-Baker microscopeA transmission interference microscope that produces interference patterns of a sample by using birefringent plates that...
meso formA form of an element that cannot demonstrate optical activity as a result of dextrogyrate and levogyrate effects that are...
grating spectroscopeA spectroscope having a diffraction grating for the resolution of light of various wavelengths.
collimated radiationRadiation in which every ray from any given object point can be considered to be parallel to every other. This is never...
thin-film waveguideA transparent dielectric film, bounded by material of a lower index of refraction, capable of guiding light.
Cotton-Mouton effectThe ability of particular pure liquids to doubly refract when influenced by a magnetic field with a direction that is...
striaeAn imperfection in optical glass consisting of a distinct streak of transparent material having a slightly different...
scientific CMOS cameraA scientific CMOS (complementary metal-oxide-semiconductor) camera is a type of digital camera specifically designed for...
hazeAn aggravated form of fog in a polished surface caused by the scattering of light. The defects causing haze are larger than...
color-sensitiveAn emulsion that can record colored light.
beamsplitting blockA glass block that produces stationary fringes in the region crossed by incident light beams.
xenonA rare gas used in small high-pressure arc lamps to produce a high-intensity source of light closely resembling the color...
fluorescence lifetime imagingFluorescence lifetime imaging (FLIM) is an advanced imaging technique that provides information about the lifetime of...
double-clad fiberDouble-clad fiber (DCF) is a specialized optical fiber that features two concentric cladding layers surrounding a core. The...
halation1. In a cathode-ray tube, the glow surrounding a bright spot that appears on the fluorescent screen as the result of the...
PockelsIn optics, the Pockels effect refers to the phenomenon where the refractive index of a material changes in response to an...
underwater television systemA television system designed to obtain pictures of objects or scenes beneath the surface of the water. Generally, a...
luminescent greenhouse collectorA collector for photovoltaic power generation that consists of a thin plate that strongly absorbs sunlight striking its...
light diffusionLight diffusion refers to the process by which light is scattered or spread out in various directions as it interacts with a...
focus lampAn incandescent or carbon arc lamp designed with a stable and compact arc or filament that permits it to be used as a light...
isogyric curvesWith respect to the effect of crystals on lightwaves, the family of curves having constant direction of polarization.
tunnel luminescenceLight that is emitted from a phosphor film applied to the surface of a three-layer thin film, respectively metal, oxide and...
marginal errorThe distortion in an ophthalmic lens resulting from the refraction of light rays entering the periphery of the lens surface....
superluminescent light-emitting diodeAn emitter based on stimulated emission with amplification but insufficient feedback for oscillation to build up.
transmission efficiencyMeasure of the amount of light that is transmitted, relative to the amount lost by absorption or reflection.
unmanned aerial vehicleAn unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot onboard. UAVs are remotely...
x-ray image spectrographyIrradiation of a cylindrical crystal with an x-ray beam resulting in Bragg diffraction that produces a slightly enlarged...
stereomicroscopyThe use of a specialized optical microscope designed to provide a more three-dimensional view of a sample. Stereomicroscopy...
scattered light filterA specific type of filter designed to reduce the amount of light scattered by reflections from the edges of optical...
photodiffusion effectThe potential difference between two areas of a semiconductor when one is exposed to light.
etendueA product of the area of a light beam (normal to its direction of propagation) and the solid angle that the beam includes;...
CMOS quantitative polymerase chain reaction systemThis type of miniaturized system, referred to as CMOS qPCR, combines microfluidic technology with an ultralow-light CMOS...
fiber lappingA method of optical fiber coupling in which the fibers are ground down to expose their cores and placed together to allow...
integrated energyAlso known as integrated exposure. A measurement of light from sources that vary rapidly with time, defined as the integral...
talbotOne lumen-second, the SI unit of the quantity of light.
near-field holographyA lithography method that allows the transfer of fine-pitch gratings from a phase mask into photoresist. The exposure takes...
scanning electron microscopeA scanning electron microscope (SEM) is a powerful imaging instrument used in scientific research, materials...
lateral effects detectorA set of photodiodes with no gaps between them that can sense the displacement of a spot of light anywhere on the sensing...
light patternIn optics, a pattern, such as the Buchmann-Meyer pattern, that may be viewed when the record surface is illuminated by a...
infrared light-emitting diodeAn infrared light-emitting diode (IR LED) is a semiconductor device that emits infrared light when an electric current...
minimum angle of deviationThe smallest angle through which light is bent by an optical element or system. In a prism, the angle of deviation is a...
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