photo Dictionary Terms
light fieldThe term light field refers to the spatial distribution of light rays traveling in all directions through a given space. It...
epitaxialEpitaxial refers to the growth of a crystalline layer on a crystalline substrate in such a way that the orientation of the...
phototherapyPhototherapy is a medical treatment that involves the use of light to treat various conditions, particularly those related...
near-infrared cameraA near-infrared (NIR) camera is an imaging device designed to capture images in the near-infrared region of the...
x-ray detectionThe collection and detection of x-rays by virtue of their ionizing properties. The ionization may be perceived directly by a...
color centerA color center, in the context of materials science and condensed matter physics, refers to a specific type of...
photovoltaic effectThe generation of a difference in electric potential between two electrodes when radiation is incident on one of them.
two-photon excited fluorescenceTwo-photon excited fluorescence (TPEF) is a nonlinear optical method that allows imaging of biological cells and living...
light dispersionThe process whereby white light is separated into its component wavelengths. Light beams of different wavelengths are...
offset prismA prism or prism assembly that serves to displace the instrument's optical axis.
magnetic resonance imagingAn imaging technique used in radiology that is based on the principles of nuclear magnetic resonance (NMR) to produce...
optical pyrometerAn instrument for determining the temperature of a hot object by examining the color spectrum of the visible light it gives...
bubble chamber opticsSpecially designed optics for the observation and photographing of hydrogen in a bubble chamber.
interferogramA photographic or electronic recording of an optical interference pattern.
galvanometric scannerA galvanometric scanner, also known as a galvanometer scanner or galvo scanner, is a type of optical scanning device used to...
negative dielectric anisotropyState typically studied in liquid crystals in which the dielectric coefficient parallel to the director is less than the...
single-photon-decay spectroscopyA technique for observing the decay of light emissions from sources following their pulsed excitations, based on recording...
single-walled carbon nanotubesReferred to as SWCNTs, these cylindrical nanostructures composed of a folded sheet of graphene can be used as near-infrared...
principal planeIn a lens or lens system, that surface at which the projections of an entering and exiting ray intersect. Also known as the...
photovoltaic detector
packing density1. In a photonic interconnect, the number of detectors in a given area. Detectors spaced too closely may give rise to...
zone plateA plate of glass, usually a photograph, on which there is a central spot surrounded by concentric annular zones, alternately...
ospinOpsins are a group of light-sensitive proteins found primarily in the retinas of vertebrate and invertebrate eyes, as well...
photovoltaic cellA photovoltaic cell, commonly known as a solar cell, is a semiconductor device that directly converts light energy into...
periscopeAn optical instrument designed to displace the line of sight in a vertical direction. For submarines and other military uses...
confocal resonatorA confocal resonator, also known as a confocal cavity or confocal laser resonator, is a type of optical resonator...
gun cameraA camera accurately aligned to a weapons system to provide a photographic record of system performance.
Airy discThe central peak (including everything interior to the first zero or dark ring) of the focal diffraction pattern of a...
revolving lens fiber optic scannerA sequential scanning device, utilizing a revolving lens, in which the cathode-ray tube image is transformed into a circle...
blackbody simulatorA source that attempts to create the characteristics of an ideal blackbody. It consists of a cavity, generally spherical,...
optical axisThe imaginary line passing through both the centers of curvatures of the optical surfaces of a lens or mirror; the optical...
nanoparticle photonic resonator absorption microscopyNanoparticle photonic resonator absorption microscopy is a microscopy technique that combines the principles of photonic...
glass film platesAn early form of photographic media consisting of glass plates coated with an emulsion.
radiation pyrometerAlso known as radiation thermometer. A pyrometer in which the radiant intensity from the source to be measured is used to...
magneto-optical photonic crystalA photonic crystal that comprises magneto-optical material such that the optical response of the device depends on the...
modulation transfer function analysis/measurement equipmentMTF analysis/measurement equipment refers to instruments and tools used to measure and analyze the modulation transfer...
multispectral photographyThe use of narrow bandpass filters and special photographic emulsions to discern features of a surface that would not be...
laser-induced fluorescenceLaser-induced fluorescence (LIF) is a spectroscopic technique that involves using a laser to excite molecules or atoms,...
photopic visionVision by means of retinal cones; color vision. Relatively high levels of luminance are required for photopic vision.
Gregorian telescopeA telescope with an ellipsoidal secondary concave mirror that reflects rays from a parabolic primary mirror through an...
pinhole cameraA lensless photographic camera that uses a small sharp-edged hole as its aperture. The light passed by this aperture onto...
stereo compilationExtraction of three-dimensional measurements from a stereo pair of photographs.
photostatic cameraA type of copying camera in which the object is placed on a horizontal easel and photographed by a horizontal camera above...
phosphorographyA process used in pyrometry and photothermometry to create a photographic record of a surface's temperature gradients....
dark-field photomicrographyA photomicrographic recording technique that utilizes dark-field illumination to render an image of an object having a...
sondeA ruggedized scintillation counter used in oil well logging. The cylindrical housing contains a gamma ray source, a...
spectral luminous efficiencyRatio of the radiant flux at a particular wavelength lm to that at any other wavelength l, such that both radiations produce...
telephotometryThe principles and techniques involved in the use of telephotometers to measure atmospheric extinction.
spectrochemical equipmentEquipment used for chemical analysis by investigation of the spectra formed and observed in chemical activity. Of particular...
wedgeAn optical element having plane-inclined surfaces. Usually the faces are inclined toward one another at very small angles....
electrolytic developmentDeveloping a photographic image by means of an applied electric field. The methods used include electrolysis and...
auto-iris lensA device for automatic exposure control in which a motor-driven diaphragm adjusts the aperture in response to a signal from...
field emission microscopeAn image-forming instrument in which a strong electrostatic field causes cold emission of electrons from a sharply rounded...
photoresponse nonuniformityNoise created by patterns imaged on a CCD surface. Pixel sensitivity is altered by responsivity during illumination.
sky filterA filter designed to decrease the luminosity of the sky without decreasing that of the landscape in the foreground. A filter...
free-carrier photoconductivityPhotoconductivity that may be extended as far as the microwave region because of the absorption of photons by electrons.
Cooke triplet lensThe simplest lens in which all primary aberrations may be corrected. It consists of two positive crown elements on either...
scientific complementary metal-oxide semiconductorScientific complementary metal-oxide semiconductor (sCMOS) refers to a type of image sensor technology specifically designed...
Bragg's lawThe law expressing the condition under which a crystal will reflect a beam of x-rays with the greatest amount of distinction...
active elementComponent that is externally controlled via electronic or photon signal.
camera tubeThe electron beam tube of a television camera that converts an optical image into a pattern of electrostatic charges and...
superresolutionSuperresolution refers to the enhancement or improvement of the spatial resolution beyond the conventional limits imposed by...
fiber optic transceiverA fiber optic transceiver, often simply referred to as an "optical transceiver," is a device used in fiber optic...
radiophotographyThe transmission of photographic images or pictures by radio waves.
electron multiplication charge-coupled device cameraAn EMCCD (electron-multiplying charge-coupled device) camera is a type of scientific camera specifically designed for...
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...
holographic lensA photographic recording of interference patterns between a plane wave and a spherical wave on a high-resolution...
Callier coefficientThe coefficient termed by Callier as the ratio between the density of photographic negatives measured by parallel light and...
vertical air photographAn aerial photograph produced when the optical axis of the camera is perpendicular to the surface below.
process cameraA photographic camera designed to produce reproduction film of visual information (pictures, line drawings, graphs) for...
Laue patternThe photographic record of the diffracted beams formed when heterogeneous x-rays emerging from a pinhole or slit impinge...
photobiomodulationA light therapy that utilizes nonionizing light sources, including lasers, LEDs, and broadband light, in the visible and...
iris diaphragmA mechanical device designed to smoothly vary the effective diameter of a lens, thereby controlling the amount of light...
differential spectrophotometryThe measurement of the spectrum bands formed by a spectroscopic sample, based on the differences between the sample and the...
solar furnaceAn optical system that is designed to produce a high temperature in a specified area by the optical direction and...
spectrum photographyThe photographic recording of visible and ultraviolet spectra on an ordinary photograph.
exposure meterAn instrument used to measure the light from a scene to be photographed and to indicate the camera lens and shutter settings...
excess noise factorA factor, F, indicating the increase in shot noise in an avalanche photodiode as compared with the ideal multiplier, which...
film planeThe site behind the lens system in a camera where photographic media are positioned for exposure.
microcombA microcomb, short for microresonator frequency comb, is a novel photonic device that generates a precise series of evenly...
double-pulsed holographyHolographic recording whereby the object is illuminated by two pulses, separated by a time interval, from a Q-switched laser...
transport theory approximationsMultiple scattering method used in biological analysis in which approximations yield simple, explicit solutions, at least...
Bunsen screenA photometer screen that contains a diaphragm of paper or parchment with a translucent central spot of oil or paraffin.
duplet lens systemAn optical system having two sets of components separated by an air space, while successive lenses in each set are cemented...
supercontinuumSupercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the...
Lloyd's mirrorA mirror employed with a very high incidence angle to form a pair of coherent light sources by reflection, and therefore...
pedestal componentPresent in photocurrent burst, it is the low frequency pulse that corresponds to the light scattered from the beams in the...
densitometryThe detection and analysis of the transmission and reflection properties of objects and photographic images.
slab laserSolid-state laser geometry in which the standard rod is replaced by a slab of laser material. Often called...
Förster resonance energy transferFörster resonance energy transfer (FRET) is a mechanism describing the transfer of energy between two closely spaced...
cascade showerA shower of cosmic rays whereby a high-energy electron produces one or more photons that convert into electron pairs, the...
colorimeterA colorimeter is a device used to measure and quantify the color characteristics of an object or a light source. It provides...
detector-Dewar assemblyA detector-Dewar assembly typically refers to a combination of a detector and a Dewar flask used in scientific instruments,...
total internal reflection fluorescenceTotal internal reflection fluorescence (TIRF) microscopy is an advanced fluorescence microscopy technique that leverages the...
spectrosensitometerA sensitometer having a continuously controlled monochromator to measure spectral sensitivity and contrast of photographic...
calcium iodideA hygroscopic powder used in the photographic process.
phototriangulation
optical design and engineering servicesOptical design and engineering services involve the development, customization, and optimization of optical systems and...
MSM photodiodeA metal-semiconductor-metal (MSM) photodiode is a type of photodetector that consists of metal electrodes on a semiconductor...
photolithographyPhotolithography is a key process in the manufacturing of semiconductor devices, integrated circuits, and...
neutral density wedgeA strip or annulus of glass coated with a semitransparent material such as inconel. The coating thickness, and as a result...
electron telescopeAn instrument that serves to produce an enlarged electron image on a fluorescent screen by focusing an infrared image of a...
mass spectrographA device that uses electromagnetic fields to separate electrically charged particles according to their masses. As a beam of...
Gauss lensA telescope objective with excellent spherochromatic correction, consisting of a meniscus crown and a meniscus flint, both...
photometryPhotometry is the branch of science that deals with the measurement of light, particularly in terms of its intensity and the...
luminescenceLuminescence is the emission of light that occurs without the involved substance undergoing a significant increase in...
degrees of freedomThe number of unique ways in which a part can move in an alignment system. In static alignment, there are six: one in the...
binocular microscopeA microscope designed with two eyepieces (oculars), permitting the use of both eyes when viewing through the instrument.
dark currentThe current that flows in a photodetector when there is no optical radiation incident on the detector and operating voltages...
dichroic coatingA dichroic coating, also known as a dichroic filter or dichroic mirror, is an optical coating designed to selectively...
stereoscopic distortionAn exaggerated depth appearance in stereo photographs caused by the lenses in the camera being farther apart than the eyes...
multijunction deviceA photovoltaic device that consists of multiple p-n junctions to produce a greater efficiency when in use than that of...
reciprocity lawWith respect to photography, the law stating that the optical density of an exposed emulsion with standard development is a...
grating spectroscopeA spectroscope having a diffraction grating for the resolution of light of various wavelengths.
custom opticA custom optic refers to an optical component that is designed, manufactured, and tailored to meet specific requirements or...
nuclear magnetic resonanceA phenomenon, exploited for medical imaging, in which the nuclei of material placed in a strong magnetic field will absorb...
achromatic prismCemented prisms of differing refractive indices which refract incident light and, due to differing refractive indices, will...
aerial filmFilm designed especially for the needs and conditions encountered in aerial photography. It is produced in a variety of...
photodarkeningThe effect that the optical losses in a medium can grow when the medium is irradiated with light at certain wavelengths.
diffraction gratingA diffraction grating is an optical component consisting of a surface with a periodic structure of equally spaced, parallel...
metasurfacesMetasurfaces are two-dimensional arrays of subwavelength-scale artificial structures, often referred to as meta-atoms or...
molecular motorA molecular motor refers to a nano-sized device composed of organic molecules or other small-scale components that can...
aerial photographyPhotographing of terrain on the ground and objects in the air by cameras mounted in aircraft; utilized in satellites,...
aerotriangulationIn aerial photography, the geometric method of indicating the three-dimensional location of ground points from a pair of...
photographic exposureThe product of exposure time and irradiance or illuminance.
Brace-Lemon spectrophotometerA spectrophotometer having a pair of identical collimators with two Glan polarizing prisms, one fixed in azimuth and the...
retina cameraA special-purpose camera used by ophthalmologists to photograph the retina of the eye. The optical system operates through...
fiber optic cable assemblyA fiber optic cable assembly refers to a complete unit consisting of optical fibers, connectors, protective jackets, and...
custom lapping and polishing servicesCustom lapping and polishing services involve specialized processes used to improve the surface finish and dimensional...
oscillogramA record formed when the luminous trace or image produced by an oscilloscope is photographed.
microwave phototubeA device designed to detect microwave modulation and to mix modulated and unmodulated laser beams. It consists of a...
electrostatic image dissectorA nonmagnetic instrument utilizing an electrofocus and deflection tube with a photocathode for imaging purposes. The optical...
tomosynthesisA variation of tomography in which several photographs of a patient are taken at different angles, and back-projection of...
microlens arrayA microlens array is a grid-like structure composed of numerous small lenses, typically arranged in a regular pattern. Each...
baselineThe smallest amount of photon energy to pass a detector window and be counted.
double-beam spectrophotometerA spectrophotometer in which the beam emitted by the radiation source is split into beams that travel through the sample and...
nanoAn SI prefix meaning one billionth (10-9). Nano can also be used to indicate the study of atoms, molecules and other...
radiographyA photographic process using x-ray radiation or the g-rays of radioactive materials.
fiber optic sensorA fiber optic sensor is a device that uses optical fibers to detect and measure physical, chemical, biological, or...
photoelectric exposure meterA device consisting of a microammeter, a photovoltaic cell and a battery. It is used for the measurement of scene brightness...
stereoscopic photographyThe photographing of a scene from positions corresponding to the locations of both eyes. A viewing device is used to present...
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...
x-ray image spectrographyIrradiation of a cylindrical crystal with an x-ray beam resulting in Bragg diffraction that produces a slightly enlarged...
photometric sphere
cesium chlorideColorless crystals used in photoelectric cells and for photosensitive material in cathodes.
acceptance angleThe range of angle or solid angle values by which light may enter an optical system.
scintillation counterAn instrument designed to measure radiation indirectly through the use of several phosphors and a photomultiplier tube. The...
spectrofluorometerAn automatic scanning instrument that is used to study a substance's fluorescence over a wide range of wavelengths. It...
wavelength shifterA photofluorescent compound that, when used with a scintillating substance, absorbs photons and emits related photons having...
Snellen letterThe letter form used on visual performance test charts. The overall letter height is equal to five times the thickness of...
emulsionIn photography, the layer of light-sensitive material (usually a suspension of silver halide crystals) that coats the film...
Schlieren photomicrographyThe photomicrographic recording of Schlieren effects, irregular refractions of light from optic surfaces or areas of thin,...
photoelectric absorptionThe transformation of incident radiant energy into a photoelectric emission current.
atomic absorption spectrometerAn atomic absorption spectrometer (AAS) is an analytical instrument used to determine the concentration of specific chemical...
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...
clinical photographyThe application of photography, with the exception of radiography, to obtain pictures of parts or the whole of a patient to...
halogen lampA halogen lamp, also known as a tungsten halogen, quartz-halogen, or quartz iodine lamp, is an incandescent lamp that uses a...
mode beatingIn optics, "mode beating" refers to an interference phenomenon that can occur in laser systems with multiple longitudinal...
photographic dosimetryThe use of photographic emulsions to detect and determine the amounts of ionizing radiation, such as x-rays and gamma rays,...
penumbraA source of light will not cast a distinct shadow of an interfering, opaque object, but will cast a shadow having two parts:...
microscope eyepieceAn eyepiece located at the near end of the microscope tube. It often is a simple Huygens eyepiece, but compensating and...
bandwidthThe range of frequencies over which a particular instrument is designed to function within specified limits. See also fiber...
electrostatic processA process used in document copying and printing that involves the visible rendering of an invisible electrostatic image on a...
negative-electron-affinity photocathodeA photocathode having a P-type semiconductor with a work function less than its bandgap. The photocathode can release a...
digital photographyA form of photography in which an electronic camera converts an image to an electronic signal that is stored in digital...
t numberThe equivalent f number of a fictitious lens that has a circular opening and 100 percent transmittance, which would give the...
holographyHolography is a technique used to capture and reconstruct three-dimensional images using the principles of interference and...
free radicalsShort-lived molecular or atomic particles, with an unpaired electron, that play an important part in many photochemical...
telephoto powerThe ratio between the focal length of a lens having a longer focal length than that of the standard lens used with a camera,...
sag1. In the geometric sense, an abbreviation for the term "sagitta,'' the height of a curve measured from the chord.
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radiation-monitoring filmThe film used in photographic dosimetry to record the types and amounts of ionizing radiation, such as x-rays and gamma...
Golay cellA thermal radiation detector consisting of a small cell with a blackened plastic front face that bulges slightly when heat...
analytical photogrammetryThe use of mathematical analysis to derive solutions in the science of photogrammetry.
optical parametric oscillatorA laser-pumped crystal with nonlinear optical properties inside of an optical resonator in which the output generates...
intrinsic photoconductivityThe absorption of a photon raising an electron across the forbidden gap from valence to conduction band of the semiconductor...
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...
infrared spectrophotometerA spectrophotometer having a prism or, more frequently, a grating for the study and recording of infrared spectra. It...
photochromicPhotochromic refers to a property exhibited by certain materials, typically organic compounds or dyes, which undergo...
triclinicWith respect to a crystal, having three unequal axes intersecting at angles, only two of which can be equal and only one of...
stereoplottingThe imaging of two photographs of a stereo pair, in complementary colors, for the preparation of contour maps.
point cloudA point cloud is a set of data points in a three-dimensional coordinate system, where each point represents a specific...
paraboloidal mirrorA concave mirror that has the form of a paraboloid of revolution. The paraboloidal mirror may have only a portion of a...
fiber optic spectrometerA fiber optic spectrometer is a device used for measuring the spectral content of light. It utilizes optical fibers to...
hyperstereoscopyA type of stereoscopic photography in which the distance between the two view points is greater than the average...
CID cameraCID, or charge injection device, camera refers to a type of imaging device that utilizes a specific kind of solid-state...
light sheet fluorescence microscopyAlso known as single plane illumination microscopy (SPIM), this process was designed for imaging of sensitive samples and...
linear positioning stageA linear positioning stage, also known as a linear stage or translation stage, is a precision mechanical device used to...
high harmonic generationHigh harmonic generation (HHG) refers to a nonlinear optical process in which intense laser light interacts with a gaseous...
scattering angleThe angle between the initial and final paths traveled by a scattered particle or photon.
photodielectric effectThe effect, present in particular phosphors, that is defined as a transformation in the dielectric constant of a material...
laser diode moduleA laser diode module is a compact device that incorporates a laser diode, optics, and often other components into a single...
mirror blankA mirror blank refers to the initial piece of material from which a mirror is made. It is typically a flat or slightly...
haze filterA filter, used in photography, that absorbs the ultraviolet and extreme blue violet radiation scattered by atmospheric haze.
photographic sensitometryThe measurement of the responsivity of photographic media and of the relations between exposure and density of developed...
crystallogramThe photographic record of the diffraction pattern formed when x-rays pass through a crystal.
night-vision deviceA device that uses low-level visible radiation or infrared radiation to produce a visual image of a night scene. These...
optical character recognitionOptical character recognition (OCR) is a technology that is used to convert printed or handwritten text into...
stochastic optical reconstruction microscopyStochastic optical reconstruction microscopy (STORM) is a superresolution microscopy technique that enables imaging of...
chalcogenideChalcogenide refers to a class of compounds containing elements from group 16 of the periodic table, which includes sulfur...
photoelectron holographyA technique proposed for studying the atomic structure of crystals by measuring the interference pattern generated when the...
xeroradiographyA printing process of electrostatic electrophotography that uses a photoconductive insulating medium, in conjunction with...
flicker photometryHeterochromatic photometry that depends on the elimination of chromatic flicker at a lower frequency than luminance flicker.
optical manufacturing tools and machineryOptical manufacturing tools and machinery encompass a wide range of equipment, instruments, and systems used in the...
PIN photodiodeA PIN photodiode is a type of photodetector or semiconductor device used to convert light signals into electrical signals....
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...
free-space optical interconnectA type of internal photonic connection in an integrated circuit in which a holographic grating is used to focus light at...
automatic recording spectrographA direct reading spectrograph having a photomultiplier assembly in place of a photographic plate. The output from the...
photoelectric effectThe emission of an electron from a surface that occurs when a photon impinges upon the surface and is absorbed. This effect...
STED microscopySTED microscopy, or stimulated emission depletion microscopy, is a superresolution imaging technique in fluorescence...
stereoscopic rangefinderA rangefinder similar to a pair of binoculars with a long base, a dot or other wander mark provided in each eyepiece field,...
dihematoporphyrin etherA photosensitizing drug used in conjunction with photodynamic therapy.
mask1. A framelike structure that serves to restrict the viewing area of the screen when placed before a television picture...
compensating filterA filter used in photography to change the spectral composition of light entering a camera, or to adjust color balance...
photoconductive detectorA device for detecting visual and infrared radiation using a photoconductor as the principle sensing element.
kron cameraAstronomical detector consisting of a photocathode isolated from the target by a coin value from which electrons are focused...
measuring eyepieceAlso known as an eyepiece micrometer. A microscope eyepiece that has a finely divided scale ruled or photographed on a...
x-ray spectrographAn instrument that is used to chart x-ray diffraction patterns, such as an x-ray spectrometer having photographic or other...
effect filterA color filter, generally used in photography, to emphasize certain color tones and to modify others in a picture for a more...
mask proximity correctionA technique used in photolithography of computer chips to compensate for errors caused by the proximity effect, which...
reflected ultraviolet photographyA photographic method used to obtain an image of a subject by means of its reflectance of incident ultraviolet radiation. An...
metalensA metalens, short for "metasurface lens," is a type of optical lens that uses nanostructured materials to manipulate light...
neutron drip linePrediction based on observations of nuclear masses in the valley of stability that indicates the maximum number of electrons...
infrared photographyThe photographic recording of images on a medium sensitive to infrared radiation, using a source capable of emitting in the...
waferIn the context of electronics and semiconductor manufacturing, a wafer refers to a thin, flat disk or substrate made of a...
Rowland circleThe circle that contains the slit, grating and primary astigmatic focus of a concave diffraction grating.
lenticular stereo photographyA type of stereoscopic photography in which a pair of lenses focuses a pair of images, relative to the positions of the two...
color perception test equipmentEquipment for testing an observer's color vision. Some tests require the identification or ordering of colored samples. The...
diode laserA diode laser is a type of laser that uses a semiconductor diode as the active medium to generate coherent light....
Glan spectrophotometerA device similar to the ordinary spectrophotometer but containing particular modifications to provide for the comparison of...
light fidelityLiFi, short for light fidelity, is a wireless communication technology that utilizes visible light or infrared light to...
concave and convex spherical mirrorConcave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These...
acutanceIn photography, the density gradient across an edge separating light from darkness, a physically measurable quantity that...
guide factorA factor derived by equating the incident light on the subject to the required incident light for suitable photography. The...
x-ray streak cameraA diagnostic instrument that uses a photocathode design to see a broad range of x-ray radiation by streaking the...
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...
light-emitting diodeAn LED, or light emitting diode, is a semiconductor device that emits light when an electric current passes through it. LEDs...
photoplethysmographyPhotoplethysmography (PPG) is a non-invasive optical technique used to detect changes in blood volume in tissues. It...
photolysis flash
photoelastic constantA formulaic description of the linear change of the reciprocal optical dielectric tensor with either stress or strain.
enzyme-linked immunosorbent assayAn enzyme-linked immunosorbent assay (ELISA) is a laboratory technique used to detect and measure the presence of specific...
Cornu double prismA compound prism formed by cementing together two 30° prisms, one of right-handed and one of left-handed quartz. It has...
photobleachingPhotobleaching is a phenomenon in which the fluorescence of a fluorophore (a fluorescent molecule or dye) is permanently...
germanium crystalGermanium crystal refers to a crystalline form of the element germanium (Ge), which is a metalloid and semiconductor...
photonic computerA type of computer in which the electronic circuits, which process data serially, are replaced by photonic circuits capable...
photorefractive materialA material in which the refractive index varies according to changes in the light to which it is exposed. Lithium niobate is...
signal-induced noiseNoise generated in the flow of current in the photomultiplier, produced by the intentional or controlled application of...
luminous energyA measure of the time-integrated amount of flux. It has units of lumen-seconds and might be used to describe such things as...
forensic photographyThe application of ultraviolet, x-ray, infrared and conventional photography to law enforcement.
bracketingIn photography, the technique of taking multiple pictures of the same subject at different exposures to compensate for...
spectrographAn optical instrument for forming the spectrum of a light source and recording it on a film. The dispersing medium may be a...
cesium phototubeA phototube having a cesium-coated cathode that has its greatest sensitivity in the infrared region.
integral densityWith respect to color photography, the measurement of the way the color film modulates the radiant flux in the optical...
gegenschein-zodiacal light photometerA photometer used to measure sky brightness and polarization associated with zodiacal light, background starlight, F-region...
curvilinear distortionA lens aberration in which the focal length varies radially outward from the center of the field. It has the effect of...
extrinsic detectorA photodetector composed of a semiconductor material whose responsive properties can be altered by the addition of...
maserAn acronym for microwave amplification by stimulated emission of radiation. Predecessor to the laser, the maser or...
image enhancing equipmentComplex devices, often involving a computer, in which a photograph is scanned by a point of light, the amplitude of the...
spectroreflectometerA spectrophotometer specially designed to measure spectral reflectance.
actinic radiationElectromagnetic energy that is capable of producing photochemical activity.
radargrammetryThe analysis of the photographs taken from the radar display of a survey aircraft and used when recording terrain that is...
actinicStimulating light used for the production of energy through photosynthesis, solar cell or other light senstitive device.
smectic phaseA form of liquid crystal in which flow does not take place in the usual manner. When examined with polarized light, the...
back-wall photovoltaic cellA photovoltaic cell designed so that light travels through the front electrode and a semiconductor before it comes to the...
spectral integral densityWith respect to color photography, the measurement, at a given wavelength, of the way the color film modulates the radiant...
spectrometerA kind of spectrograph in which some form of detector, other than a photographic film, is used to measure the distribution...
eyeThe organ of vision or light sensitivity.
area scanArea scan, in the context of imaging and cameras, refers to a method of capturing an entire two-dimensional image in a...
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...
optical profilerAlso known as a white-light interferometer. Measures surface texture and shape from nanometer-scale roughness to...
infrared light sourceAn infrared light source is a device that emits light in the infrared spectrum, which lies beyond the visible spectrum of...
representative fractionRatio between map or photo linear distance and the actual ground dimensions represented.
proximity effectThe underexposure caused by the diffraction of light passing through small openings spaced closely together in masks used in...
bismuth silicon oxideA photorefractive material used in image processing, holography and optical switching.
astronomical spectrographAn instrument that photographs the spectra of an extraterrestrial object.
photronic cellA photovoltaic cell usually sensitive to infrared radiation. It may have a copper base and a film of cuprous oxide. When it...
normalized frequencyAlso referred to as the V number in fiber optics; the normalized frequency is a dimensionless quantity, denoted by the...
Wiener experimentAfter putting a thick photographic emulsion on a front-faced mirror, and exposing the emulsion to monochromatic incident...
photoelectric cathodeA cathode principally designed to emit a photoelectric current.
ophthalmic instrumentsA family of specialized instruments used by ophthalmologists and optometrists to study a patient's eyes and prescribe...
photomorphogenesisThe study of the effects of light on the growth and development of various plants.
Raman absorptionThe absorption of part of the photon energy by a molecule through which there is a slight energy change and the energy...
superior mirageAn image of an object that appears above the object's true position as the result of abnormal refraction of the image rays...
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...
single-photon avalanche diodeA single-photon avalanche diode (SPAD) is a specialized type of photodetector designed to detect extremely weak optical...
Paschen-Runge mountingA mounting used for large concave gratings, whereby the slit, grating and plate holder lie in the Rowland circle, and the...
actinometerA device that measures the intensity of photochemically active radiation, particularly from the sun. One form of this...
autocollimatorAn autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on...
averaged threshold receiverA receiver for optical communications systems consisting of a symmetric binary, pulse-code-modulated transmitter, a...
luminance meterA type of photometer calibrated in luminance units (candles per square unit, or lamberts). In photography an exposure meter...
optical fiber optic switchesOptical fiber optic switches are devices used in optical fiber communication systems to selectively route optical signals...
stellar photometryThe utilization of photometric measurement to determine the relative magnitudes of the heavenly bodies.
cesium oxide cellA photoemissive detector sensitive to wavelengths up to 1 µm. It has one sharp maximum of sensitivity at 350 nm and a...
biocularA term pertaining to devices (generally optical) designed for use with both eyes viewing through a single exit pupil. The...
phototoxicityPhototoxicity refers to the harmful effects caused by exposure to light, particularly intense or ultraviolet (UV) light, on...
picosecond spectroscopyA method of measuring complex sequential photosynthetic reactions by varying the pulse time and wavelength of light...
gas magnificationThe increase in current of a phototube as a result of the gas in the tube becoming ionized.
Lissajous patternThe pattern, formed by a character generation cathode-ray tube system, in which the characters are made up of wave shapes...
exciter filterIn ultraviolet and fluorescence photography, the term applied to the filter used in the photographic system and with the...
simultaneous exposure and developmentThe process, used with a positive photoresist, in which the photoresist is immersed in developing chemicals while being...
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...
single-molecule FRETSingle-molecule Förster resonance energy transfer (smFRET) is a specialized technique in biophysics and molecular...
electron micrographThe photographic recording of images produced by the electrons from an electron microscope. The electron beam carries the...
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...
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...
spectrophotometric analysisThe detection and measurement of spectral reflectance, spectral transmittance or relative spectral emittance, relative to...
photoclinometerA photographic recording instrument that measures deviation from the vertical of a drilled well or mine.
photoelectric photometerAlso known as electronic photometer. A photometer with a photocell, phototransistor or phototube for measuring the intensity...
photothermal effectThe cause of some forms of laser injury in which tissue absorbs incident laser light and experiences a damaging rise in...
quantum cascade laserA quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics....
internal photoeffectThe effect in which photons are absorbed and excite the electrons; the electrons move from the valence band to the...
ion laserA laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized...
harmonic generationHarmonic generation refers to a nonlinear optical process in which incoming photons interact with a material and produce new...
image tube cameraA camera system in which the image formed on the fluorescent screen of an image converter tube in the system is recorded by...
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...
microphotonicsThe technology of manipulating light on a micro scale. In optical communications, this is usually accomplished using two or...
film recorderAn instrument designed to place nongraphic information, usually generated by a computer, onto photographic film. The...
GRIN lensA GRIN (gradient index) lens is a type of optical lens that utilizes a gradient in refractive index across its volume rather...
Twyman-Green interferometerA testing device that provides a contour map of the emergent wavefront for the observer in terms of the given wavelength of...
photoelectric emissionThe electron emission from a substance or instrument whose surface has been bombarded by a suitable amount of radiation.
image intensifierAn image intensifier, also known as an image intensification tube or image intensification device, is a specialized...
monitor currentIn a laser diode, the photocurrent produced by a photodiode that detects the emission from the rear facet of the...
comparator1. An eyepiece or magnifier with a scale at its image plane. That scale is placed in contact with an object, permitting...
head-up displayAn optical system that superimposes a synthetic display providing navigational or weapon-aiming information on a pilot's or...
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...
Mach-Zehnder interferometerA Mach-Zehnder interferometer is an optical device used to measure the phase difference between two collimated beams of...
Cassegrain lens systemA two-mirror lens design used in astronomical telescopes, the primary being a parabola, the secondary a smaller hyperbola....
chroma1. Attribute of a visual sensation that permits a judgment to be made of the amount of pure chromatic color present. 2. The...
second-order nonlinear optical propertiesSecond-order nonlinear optical properties refer to a class of phenomena exhibited by certain materials in response to...
photonicsThe technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon. The...
binary opticsOptical elements, often created by micromachining, lithography or vacuum deposition, that rely on diffraction of the...
multi-axis alignmentMulti-axis alignment refers to the process of aligning or adjusting components or systems in multiple spatial dimensions or...
retina1. The photosensitive membrane on the inside of the human eye. 2. A scanning mechanism in optical character generation.
goniophotometerA device used to measure directional reflectance, with light collection restricted to a narrow range of angles of which the...
effective beamIn photoelectric sensing, the portion of the transmitted beam that actually functions in the system; the diameter of the...
phase-contrast microscopeA microscope that has an annular stop in the lower focal plane of the condenser, and a quarter-wave retarding and absorbing...
opaque projectorAn opaque projector is a device used for enlarging and projecting images from opaque objects such as printed pages,...
optical materialsOptical materials refer to substances or compounds specifically chosen for their optical properties and used in the...
double-Gauss lensA fast, wide-angle lens used in television and photographic cameras, with excellent overall correction, but subject to...
color temperature meterA device containing two photocells behind deep red and blue filters to measure color temperatures. The amplifier gain is...
Barlow lensA negative lens used to increase the effective focal length of a telescope objective.
photodarlingtonA Darlington current amplifier consisting of two separate transistors, of which a phototransistor is the input device.
x-ray diffractionThe bending of x-rays by the regular layers of molecules in a crystal acting like a very small diffraction grating. The...
cone1. A solid figure whose base is a circle and whose sides taper upward evenly to a point or apex. Light rays diverging from...
color comparator1. A device used in chemistry to compare the colors of solutions held in flat-bottomed tubes and viewed along the length of...
optical densityA measure of the transmittance through an optical medium. Optical density equals the log to the base 10 of the reciprocal of...
photoelectric densitometer
superfluorescenceThe process in which the normal rate of fluorescent emission from a substance is enhanced by virtue of the optical gain of...
laser velocimeter signal detectionThe variation of the electronically detected signal with respect to the scaled version of the classical optical signal...
bubble chamberA large tank filled with liquid hydrogen, with a flat window at one end and complex optical devices for observing and...
fluorographic cameraA camera with a very high aperture lens or mirror system for photographing x-ray fluorescent screen images, mainly to save...
frame rateFrame rate refers to the frequency at which consecutive images, or frames, are displayed in a video sequence. It is...
photoelectric sensitivityThat property of a material that determines its ability to release electrons when absorbing photons.
third-order theoryCalculations of lens aberrations whereby the first two terms of the series expansion
are the only ones employed....
film readerA device used to scan images or information on photographic film for the subsequent relay of information.
Abbe refractometerDevice which measures the index of refraction of glass as well as the dispersion over visible range.
proximity-focused image tubeA planar photocathode and a planar phosphor screen mounted in a close-spaced parallel configuration in an evacuated...
Clayden effectThe desensitization of the first photographic exposure after it has been subjected to high-intensity radiation.
optical time-domain reflectometryA method for characterizing a fiber wherein an optical pulse is transmitted through the fiber, and the resulting light...
alloy-junction photocellA photocell having an alloy junction formed by combining an indium disc with a thin wafer of N-type germanium.
optical coherence tomography imaging systemOptical coherence tomography (OCT) is an imaging technique used in medical diagnostics and biomedical research to obtain...
GaAlAs laserA GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic...
micro-opticsMicro-optics refers to the design, fabrication, and application of optical components and systems at a microscale level....
photorefractive keratectomyA surgical procedure for correcting vision by reshaping the outer surface of the cornea through the use of a laser system.
nuclear track emulsionA photographic emulsion of the silver-halide type that is used to record the path of a charged traveling particle. The...
APD detectorAn APD detector, or avalanche photodiode detector, is a type of photodetector used to detect light or optical signals by...
radiographic amplifier screenA solid-state panel of the photoconductor-electroluminescent type. The photoconductive layer, sensitive to x-rays, is coated...
microphotometryThe measurement of the intensity of spectral lines by the examination of a very small area under a microscope and the...
second-harmonic generationSecond-harmonic generation (SHG) is a nonlinear optical process that occurs when two photons with the same frequency combine...
relay condenserA form of lens assembly used in a projection system to maximize efficiency and assure uniform illumination of the object...
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...
optoisolatorAn optical coupling device that uses light to bridge the gap between incompatible wire communications systems. It contains...
Luneburg lensA dielectric sphere with an index of refraction that varies with distance from the sphere center. A parallel beam of rays is...
rear facet monitorA photodetector mounted in the same package as a laser diode that is positioned to monitor the output from the rear facet of...
thermophotovoltaicThermophotovoltaic (TPV) refers to a technology that converts heat energy into electricity using the principles of...
semitransparent photocathodeA photocathode that receives radiation from one side and emits a photoelectric current from the opposite side.
modulation spectroscopyA method of spectral analysis in which some property of the sample is varied and the corresponding change is measured. The...
infrared vidiconA vidicon that has a photoconductive surface that can be excited by infrared radiation.
infrared mappingThe process of mapping the infrared emittance of an area through the use of an infrared detector and related scanning...
molded lensA molded lens is an optical lens manufactured using a molding process, typically involving the shaping of a material, such...
photodynamic therapyA medical technology that uses lasers or other light sources in combination with photosensitizing drugs to treat cancerous...
antireflection coatingAn antireflection coating (AR coating) is a thin film or coating applied to optical surfaces, such as lenses or windows, to...
optical gratingAn optical grating, in the context of optics and physics, refers to a device with a periodic structure of closely spaced,...
optical data storageThe storage of information via optical means, primarily employing a low-power laser to inscribe data on a photosensitive...
monochromatorA monochromator is an optical instrument used to isolate and select a narrow range of wavelengths from a broader spectrum of...
ultraviolet photoemission spectroscopyA technique for measuring the energy spectrum of electrons emitted during the absorption of ultraviolet radiation. This...
bench photometerA device used to compare the luminous intensities of two sources by locating a point between the two light sources where the...
line-scan cameraA line-scan camera, also known as a line-scan image sensor or linear array camera, is a type of digital camera designed to...
shunt resistanceIn a silicon photodiode, the dynamic resistance (dv/d1) of the junction at zero volts.
photochemical hole burningA method of producing disks for erasable optical data storage. Information is recorded by a laser beam that generates pits...
resolution targetA chart on paper or glass containing a series of sets of lines at progressively smaller spacing and used to ascertain the...
anamorphoscopeA cylindrical convex viewing mirror used for viewing distorted pictures formed by photographing the reflections of the...
xerographyA printing process of electrostatic electrophotography that uses a photoconductive insulating medium, in conjunction with...
edge-emitting LEDAn edge-emitting light-emitting diode is a type of LED structure where light emission occurs primarily along the edge of the...
acoustical holographyThe optical reconstruction of image information contained in a sound field. First the diffraction pattern, formed by an...
telephotometerAn instrument used to measure the luminance (brightness) of a distant object. The object is viewed through a small...
brightness meterAn instrument for measuring the brightness (luminance) of a scene. It may be a spot meter, covering an area of a degree or...
ultraprecision cathode-ray tube displayA highly accurate cathode-ray tube used to display information with the utmost efficient stability and resolution. The...
Ritchey-Common testAn interferometric method for describing the surface shape of large coated or uncoated optical flats. The procedure uses a...
reversed telephoto lens
Sagnac interferometerA type of interferometer in which two coils of optical fiber are arranged so that light from a single source travels...
vacuum phototubeA phototube that functions within a vacuum and thus eliminates the effects of gaseous ionization on its electrical...
diazo filmA type of photographic film, often used in microfilming, that is processed by heat treatment, needing no liquid application.
solid-state imaging systemAn imaging system that uses a mosaic of tiny light-sensitive semiconductors (phototransistors) to produce individual outputs...
photocoupler
Nipkow disc scannerA device consisting of a disc with a spiral arrangement of holes that is used to convert visible patterns into electrical...
optical correlatorA device incorporating a spatial light modulator and a reference filter; used for matching an input optical waveform or...
photoreflectanceA noncontact form of electromodulation in which modulation of the electric field is caused by photo-excited electron-hole...
mode filterA device used in measuring the attenuation of multimode optical fibers. A short reference length of fiber when combined with...
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...
sequence cameraA type of motion-picture camera in which single frames are photographed either automatically at a predetermined rate (as...
Gaussian profileAn intensity distribution (intensity as a function of radial distance from the beam center) which is given by the Gaussian...
landolt ringA broken circle used as the test object in distinguishing visual acuity. The width of the gap in the circle is equal to the...
zoom lensAn optical system of variable focal length, the focal plane remaining in a fixed position. This result is achieved by moving...
photodiffusion effectThe potential difference between two areas of a semiconductor when one is exposed to light.
photoemissive detectorAn electronic tube instrument in which the anode current varies with the intensity of light incident on the cathode.
dichroismDichroism refers to the property of certain materials to exhibit different colors or absorbance of light depending on the...
microscopeAn instrument consisting essentially of a tube 160 mm long, with an objective lens at the distant end and an eyepiece at the...
band-to-band photoluminescenceThe emission of a photon by the return of an excited carrier from the conduction band to the valence band of a semiconductor...
polaritonA polariton is a quasiparticle resulting from the strong coupling between photons (light particles) and certain types of...
ultrafast laserAn ultrafast laser is a type of laser that emits extremely short pulses of light with durations typically on the order of...
thermographThe instrument used to collect thermal radiation information on an object by scanning. It consists basically of a detector,...
astronomical photographyThe use of photographs to record astronomical objects and phenomena for purposes of physical observation and measurement of...
reticleAn optical element located at an image plane, containing a pattern that assists in pointing an instrument or measuring...
diffuserAn optical diffuser is an optical component or material designed to scatter or diffuse light that passes through it. It is...
visibility meter1. An instrument used to determine the visual range in an environment. 2. A type of photometer that artificially reduces an...
epitaxial equipmentEpitaxial equipment refers to a set of specialized tools and systems used in the process of epitaxy, which is the growth of...
prismA prism is a transparent optical element with flat, polished surfaces that refract light. It usually has two parallel bases,...
fiber optic imaging bundleA fiber optic imaging bundle is a specialized optical device composed of multiple optical fibers bundled together. Each...
quantum photodetector
infrared detectorAn infrared detector is a device that is used to detect and measure infrared radiation, which lies beyond the visible...
holographic cameraA holographic camera, also known as a holographic imaging system or holographic recorder, is a specialized device used to...
flying spot microscopeA microscope that uses a flying spot scanner, directed through the eyepiece, as a light source to determine the features of...
acousto-optic modulators and deflectorsAn acousto-optic modulator (AOM) is a device that utilizes the interaction between sound waves and light waves to modulate...
planetary cameraA camera system used for microphotography in which the document to be recorded is on a flat bed, perpendicular to the lens...
cosine law of illuminationLaw relating the illuminance (or irradiance) of a surface to the cosine of the angle, q, between the normal to the surface...
gainAlso known as amplification. 1. The increase in a signal that is transmitted from one point to another through an amplifier....
fluenceFluence is a term used in various scientific and technical disciplines to describe the amount of something per unit area....
high-speed movie cameraA camera designed to record at rates exceeding 50 fps. For frame rates up to about 500 fps, an ordinary pull-down mechanism...
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...
microphotometerAn instrument capable of measuring the transmitted or reflected luminance from a very small area seen under a microscope....
multiphoton processA process involving the interaction (absorption, emission or both) of two or more photons with a molecular entity.
spectroscopic flashThe light flash, produced in flash photolysis, that is triggered within a second discharge tube by the third electrode. It...
cascade methodA heterochromatic photometric process using successive comparison of similar chromaticities and the calculation of relative...
femtosecond laserA femtosecond laser is a type of laser that emits ultrashort pulses of light with durations on the order of femtoseconds,...
hybrid image recording deviceA single housing that includes means of recording an image photographically and electronically.
solar cellA device for converting sunlight into electrical energy, consisting of a sandwich of P-type and N-type semiconducting...
analytical phototriangulationThe use of photographs taken from specially placed cameras, to develop, through computation, a spatial solution of 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...
electro-optic detectorA device that detects radiation by utilizing the influence of light in forming an electrical signal. It may be a phototube;...
quantum efficiencyQuantum efficiency (QE) is a measure of the effectiveness with which a device or system, typically in the context of...
comparison lampA reference incandescent light source having a luminous intensity that is used in photometry for comparison of other light...
diffractionAs a wavefront of light passes by an opaque edge or through an opening, secondary weaker wavefronts are generated,...
steradianThe unit solid angle subtended at the center of a sphere by an area on its surface equivalent to the square of the radius;...
quantum opticsThe area of optics in which quantum theory is used to describe light in discrete units or "quanta" of energy known as...
atom opticsThe area of optics in which the wave nature of a particle is exploited to carry out very accurate interferometry and other...
alphanumeric readerAn instrument that reads alphabetic, numerical and special characters by means of a photosensor that measures the varying...
loose-tube bufferingIn fiber optic cable, containment of the fiber or fibers within an outer protective tube in which they can move to some...
CCD cameraA CCD camera, or charge-coupled device camera, is a type of digital camera that utilizes a CCD image sensor to capture and...
cineradiographyThe photographic filming of the action of x-ray images recorded on a fluorescent screen by means of large lens apertures and...
wedge ring detectorA diffraction pattern sampling unit composed of a 32-element monolithic silicon photodiode array and a readout unit. The...
rasterThe pattern of lines traced by rectilinear scanning in display systems.
slit-width errorThe error inherent in spectral energy or spectrophotometric quantity due to the finite dimension of the entrance and exit...
photonegativeThe property exhibited by a substance having electrical conductivity that decreases as the intensity of the incident visible...
high-speed shutterA shutter actuated by means other than mechanical springs for timings on the order of nanoseconds. The shutter is used in...
photoelectric constantThe constant that, multiplied by the frequency of the radiation-producing emission of photoelectrons, determines the amount...
photoelectric mixingAlso known as light beating. The mixing of two narrowband optical components to produce an AC component in the photocurrent...
computer-generated hologramA computer-generated hologram (CGH) is a holographic image produced using computational methods and algorithms, rather than...
laser paintingExtended period exposure photographs of a laser light created with various patterns within full image (laser graffiti).
sunlight recorderAn instrument consisting essentially of a photoelectric cell filtered to respond to a specified wavelength region, an...
magnetically focused image tubeA vacuum tube in which a magnetic field is superimposed onto the tube's electrical field. When the two fields are aligned,...
image jumpIn optics, the term image jump refers to a displacement or shift in the apparent position of an image when a change occurs...
Huefner spectrophotometerA visual spectrophotometer with a rhomb located directly before the entrance aperture of a constant-deviation...
ophthalmoscopeAlso referred to as a funduscope, an ophthalmoscope is a specialized instrument used by ophthalmologists for observing and...
ultraviolet densitometryA technique, involving spectrophotometry in the ultraviolet, that is designed to determine the colors of thin-layer...
mercury arcAn electric arc that is formed in mercury vapor through which an electric current flows. The intensity of the illumination...
spot photometer
cesium-antimonide photocathodeA photocathode that exhibits maximum sensitivity in the blue and ultraviolet regions of the spectrum. The sensitivity is...
Senarmont prismA polarizing beamsplitting prism similar in design to the Rochon prism. However, the Senarmont transmits the extraordinary...
Billet's split lensAn experimental lens used to produce interference fringes. A positive lens is cut into halves along its center, and the...
phototube relayA photoelectrical relay that uses a phototube as its photoelectric device to open and close an electrical relay; used to...
scanning headA device composed of a light source and phototube used to scan a moving strip of material in photoelectric side-register...
scanner1. A device used to trace out an object and build up an image. One of the most common of these types is video scanning. The...
photoluminescenceThe state of optically excited luminescence. Luminescence refers to the light emitted by excited atoms or ions as they decay...
liquid crystal light valveA liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the...
Schlieren photographyThe formation of a picture or image in which the density gradients in a volume of flow are rendered visible. The image is...
equatorial mountA telescope stand equipped with a polar axis that can be set parallel to the Earth's axis of rotation and a declination axis...
infrared opticInfrared optics refer to optical components and systems designed to manipulate and control infrared (IR) light, which lies...
analytical photographyThe use of photographs -- motion picture or still -- to establish if a particular event exists.
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°...
secondary colorAn aberration that remains after primary color is corrected. Primary color causes the back focus of a lens to vary with...
blackbody sourceA blackbody source, often simply referred to as a blackbody, is a theoretical or practical physical object that absorbs all...
photoacoustic imagingAbbreviated PAI. An imaging modality with a hybrid technique based on the acoustic detection of optical absorption from...
spherical aberrationSpherical aberration is an optical aberration that occurs when light rays passing through a lens or curved optical surface...
electroluminescenceThe nonthermal conversion of electrical energy into light in a liquid or solid substance. The photon emission resulting from...
short-arc lampA compact high-pressure light source in which an electrical discharge between electrodes spaced no more than 12 mm apart...
overhead projectorA projector used to project transparencies. A horizontal 8 x 10-in. stage for writing or laying down preformed...
contrastThe apparent difference in brightness between light and dark areas of an image. For a light target against a dark...
photomaskA photomask, also known simply as a mask or reticle, is a key component in the photolithography process used in...
fall timeMeasurement of the interval during which a photodetector's signal and output current drops from 90 to 10 percent.
photoelectric currentThe electron stream emitted by a phototube when the cathode is exposed to light.
isotopically selected laser spectroscopyA spectroscopic technique in which an excitation band absorbs laser energy resulting in an electronic transition. The...
step-and-repeat printerA projection printer that is capable of reproducing a multiplicity of images from a master transparency on a single support...
quantumThe term quantum refers to the fundamental unit or discrete amount of a physical quantity involved in interactions at the...
exciter lampA small incandescent lamp whose intense beam is focused on the optical soundtrack of a motion picture film. The soundtrack...
two-photon polymerizationTwo-photon polymerization (TPP) is a technique used in additive manufacturing, specifically in the field of 3D printing. It...
high-speed photographyPhotography involving the recording of events that occur too fast to be perceived by the human eye or recorded by...
FTIR spectrometerFTIR (Fourier transform infrared) spectrometer is a powerful analytical instrument used to obtain an infrared spectrum of...
intensified charge-coupled device cameraAn intensified charge-coupled device (ICCD) camera is an advanced imaging device that combines the capabilities of both an...
metric photographyThe photographic recording of objects or events in a manner that allows quantitative information to be derived from the...
lead sulfide cellA photoconductive cell having greatest sensitivity in the infrared region. The photosensitive material of the cell is lead...
transparent electrophotographic filmsImaging materials that generally consist of a polyester base, a transparent electrically conductive layer and an organic...
Lummer-Brodhun cubeA photometric instrument having two prisms clamped in optical contact to produce a photometric field with an acute dividing...
eye reliefAlso termed eye distance. The distance between the vertex of the last optical surface of a visual optical system and the...
einsteinA unit of energy equal to the amount of energy absorbed by one molecule of material undergoing a photochemical reaction, as...
optoelectronic integrated circuitA monolithic device containing both photonic and electronic sources, detectors, modulators, etc., on a single semiconductor...
photoemissive tube photometerA photometer that uses a photoemissive tube to detect and measure light. See photoelectric photometry.
Kellner eyepieceAn eyepiece consisting of a planoconvex field lens and a cemented doublet as the eye lens.
laser active elementsLaser active elements typically refers to the substances or materials within a laser system that play a critical role in the...
wide-angle lensA wide-angle lens is a type of camera lens that has a shorter focal length than a standard or normal lens, allowing it to...
photographic radiometryThe use of photographic recording equipment to measure radiant energy. With this procedure, many measurements of radiant...
fog1. A term used to describe the clouded appearance of an incompletely polished surface that scatters light. 2. The...
indium phosphideIndium phosphide (InP) is a compound semiconductor material composed of indium (In) and phosphorus (P). It belongs to the...
inverted telephoto lens
self-phase modulationSelf-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a...
light-powered telephoneTechnology that relies on a highly efficient photodetector that can detect incoming light signals at one frequency and...
storage timeInterval between cutting off a photoconductor's signal and the fall of current output to 90 percent.
ring-laser gyroscopeA solid block of glass-ceramic material with holes drilled the length of all four sides, and mirrors attached to the corners...
integrated photonicsIntegrated photonics is a field of study and technology that involves the integration of optical components, such as lasers,...
viewing filterA filter, pale purple in color, used in black and white photography to display the brightness values of a subject being...
Fabry-Perot interferometerA multiple-beam interferometer, usually consisting of two flat plates, with high reflective ability. The plates are set...
photoelectromagnetic effectInteraction of a magnetic field with a photoconductive substance exposed to light to create a potential difference.
saturation1. The decrease of the absorption (or gain) coefficient of a medium near some transition frequency when the power of the...
spectral repeatabilitySpectral repeatability refers to the consistency and reproducibility of spectral measurements across multiple trials or...
comaA lens aberration, resulting from different magnifications in the various lens zones, that occurs in that part of the image...
off-axis paraboloid and ellipsoid mirrorOff-axis paraboloid and ellipsoid mirrors are specialized optical components used in various optical systems, particularly...
latent imageThe pattern of physical or chemical changes that has taken place in a photographic emulsion, by its exposure to light, that...
shutter speed testerA device used to measure the opening time of a shutter. The most common devices depend on the charging or discharging of an...
thick-phase materialA type of recording material, usually a photodielectric polymer, offering in situ development mechanisms because of its...
detector arrayA detector array refers to a collection of individual detector elements arranged in a two-dimensional grid or matrix format....
oscillographAn instrument used to record rapidly varying currents or voltages. An oscillograph may consist of a cathode-ray tube...
indirect radiative transitionAn energy transition concerned with the combination of a photon and a phonon.
nodal pointsOf all the rays passing through a lens from an off-axis object point to its corresponding image point, there is always one...
fluorescenceFluorescence is a type of luminescence, which is the emission of light by a substance that has absorbed light or other...
transverse modeIn the context of optics and lasers, a transverse mode refers to a specific spatial pattern of the electric field within the...
curvature of fieldA lens aberration that causes a flat object surface to be imaged onto a curved surface rather than a plane.
characteristic curveA graph used in photography to portray the increase of a film's density as its time of exposure increases.
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...
intravital microscopyIntravital microscopy is an imaging technique used to visualize biological processes within living organisms, typically in...
photoconductive cell
nanoLEDAn LED (light-emitting diode) is a semiconductor device that emits light when an electric current passes through it. LEDs...
suprathermal ion detectorA mass spectrometer used to detect ions formed by photo- and charge-exchange ionization of gases, such as those in the lunar...
photoelectric pyrometerAn instrument used to measure the temperature of a source through the use of photoelectric cells to detect and measure the...
lateral colorLens aberration resulting in image size variation as a function of wavelength. See also chromatic aberration.
phase conjugationThe use of a reflective device, which can be fashioned from a variety of materials including gases, solids, dyes, aerosols,...
polarization-preserving fiberSingle-mode fiber that preserves the plane of polarization of the light launched into it as the beam propagates through its...
high-speed motion cameraA high-speed motion camera, also known as a high-speed camera or slow-motion camera, is a specialized imaging device...
retinographyThe process of photographing the retina of the eye.
image-enhancing equipmentComplex devices, often involving a computer, in which a photograph is scanned by a point of light, the amplitude of the...
powder cameraA camera system that uses a fine powder to diffract x-rays from the specimen. A beam of monochromatic x-rays passes through...
prism binocularsA pair of telescopes with prismatically erected images, mounted side by side with the eyepieces at the interocular distance...
spectrophotometerA spectrophotometer is a scientific instrument used to measure the intensity of light at various wavelengths in the...
biophotonicsThe technology that deals with the interaction of organic materials with light and other forms of radiant energy whose...
filter spectrophotometerA spectrophotometer that makes use of filters to isolate narrow bands of the spectrum.
grating monochromatorAn optical instrument used to isolate a narrow bandwidth of optical radiation using a diffraction grating as the dispersive...
photometric equipmentPhotocells of various kinds used to measure photometric quantities; i.e., intensity, luminance and illuminance. Meter...
Bohr's frequency relationThe law given by the formula:
that is, the frequency of radiation emitted or absorbed by a system when E2 and E1...
aerial surveyThe creation of a planned sequence of data input that is obtained while airborne for use in aerial photogrammetry and other...
phototelegraphyA document-transmitting process that uses a cylinder that rotates the document to be scanned and detected by a photoelectric...
ultraviolet microscopyThe study and photographing of microscope specimens in ultraviolet light; using an optical microscope containing fluorite...
false color processEntirely analogous to color photography, but inclusive of light bands that do not appear in the visible spectrum.
field emission displayAn X-Y electrically addressable series of arrays with individual electron emitters bombarding a phosphor-coated transparent...
flame photometryA part of the spectrochemical analysis of a sample that deals with the excitation of that sample by flame analysis.
electro-optic modulatorAn electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an...
hybrid circuitAny integrated circuit that also makes use of one or more discrete components; frequently used to describe circuits that...
direct radiative transitionAn energy transition concerned with photons alone.
Amici prismAlso known as roof prism. A type of prism designed by G.B. Amici. It consists of a roof edge produced upon the long...
topological photonicsTopological photonics is a branch of physics and optics that explores the application of topological concepts to the...
alexandrite lasersAn alexandrite laser is a solid-state laser that utilizes a synthetic crystal made from the rare earth element alexandrite...
fluorescence photographyThe photographic recording of a subject that exhibits luminescence only for an extremely short time (10-8 s) after the...
snooperscopeAn instrument used for viewing in low levels of illumination by means of infrared radiation. A high-aperture lens forms an...
photopolymer hologramA holographic plate coated by photopolymeric mixtures that are composed of one or more monomers and a photoredox catalyst...
external photoelectric effectThe ejection of electrons from the surface of a solid by the absorption of a sufficient amount of photons.
barrel distortionThe negative distortion that causes a square grid pattern to be imaged as barrel-shaped.
photoisolator
acetate filmAlso cellulose acetate film. The emulsion layer applied to the substrate of a photographic surface. The emulsion layer is...
holographic gratingA holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists...
dispersive powerA measure of the dispersive properties of a glass. The relative dispersion is defined as:
where C, D, and F refer to the...
Fresnel mirrorsTwo plane mirrors that are not wholly located in the same plane. When light from a point source or slit reflects from the...
indium gallium arsenide cameraAn InGaAs (indium gallium arsenide) camera is a type of imaging device that utilizes InGaAs sensors to capture images in the...
bolographA bolometer that serves to record. The photographic record formed by the bolometer may be called bolograph or bologram.
resonatorA resonator is a device or system that exhibits resonance, which is a phenomenon that occurs when an external force or...
nanophotonicsNanophotonics is a branch of science and technology that explores the behavior of light on the nanometer scale, typically at...
lens elementOne optical element of a multielement lens. See optical element.
radiophotoluminescenceThe luminescence displayed when particular minerals are irradiated with β-rays and g-rays, after being exposed to...
fiber photometryAn optical recording technique that uses light source(s), a beamsplitting cube, light detector(s) and an optical fiber...
radiophotographA photograph transmitted by radio waves.
cold shieldThat part of an infrared detector-Dewar assembly that limits the solid angle viewed by the sensor; it is maintained at a...
optical interconnectionThe use of photonic devices rather than electronic devices to make connections within and between integrated circuits.
luminescent greenhouse collectorA collector for photovoltaic power generation that consists of a thin plate that strongly absorbs sunlight striking its...
responsivityThe gain that occurs between light intensity incident on a CCD given by the photocurrent produced.
idiochromaticPertaining to the possession of photoelectric characteristics as a result of the properties of the true crystal and not of...
breakdown voltageIn avalanche photodiodes, the point at which an increase in the reverse bias voltage causes the current gain to approach...
Snell's law of refractionThe incident ray, the normal to the refracting surface at the point of incidence of the ray at the surface, and the...
photogrammetryPhotogrammetry is a technique used to obtain accurate three-dimensional measurements of objects and environments through the...
assist gasA gas, such as oxygen, that improves the speed and efficiency of a laser cutter or welder when applied to the work surface,...
crystal spectrographA system that applies a crystal as a diffracting agent to photograph the spectrum.
x-ray image intensifierAn image intensifier that consists of an evacuated tube with a large input phosphor screen at one end. The phosphor screen...
imaging scienceThe science of producing, recording, storing, transmitting and displaying visual images by any system (photographic, video,...
beamsplitterA beamsplitter is an optical device for dividing a beam into two or more separate beams. A simple beamsplitter may be a very...
achromatic lensA lens consisting of two or more elements, usually of crown and flint glass, that has been corrected for chromatic...
safelightFiltered light to which photographic or other photosensitive materials are not responsive; used to illuminate darkrooms when...
photositeA small section of the surface of a sensor corresponding to a single pixel in the image.
Schmidt cameraA camera that consists of a concave spherical mirror with an aspheric plate situated at the center of curvature of the...
electron-beam recordingThe recording of the information contained in a modulated electron beam onto photographic or silicon resin-coated materials....
laser photocoagulatorOptical source intended to reduce bleeding as well as to abet wound or vessel healing through cauterization, used in eye...
Munsell notationAlphanumerical description of color according to Munsell hue, value and chroma.
pair productionThe production of a positron-electron pair by a photon having energy greater than one mega-electron-volt, whereby some of...
photoelasticityThe process of determining, with the aid of plane-polarized light, the stress distribution in materials under complex...
ophthalmic photographyThe methods and techniques used to obtain medical photographs of the human eye. To photograph the exterior of the eye,...
Petzval lensA high-speed, narrow-field lens consisting of two achromats spaced about the aperture stop. Its uses include portrait...
photogrammetric equipmentThe special cameras, film and other means for forming maps by aerial photography.
plasmon ion-assisted depositionPlasmon ion-assisted deposition (PIAD) is a technique used in thin-film deposition processes, particularly in the production...
photomicrographic cameraA still or motion-picture camera designed to photograph through a microscope. Photomicrographic equipment usually contains a...
panchromatic photographic filmBlack and white film that has a wavelength sensitivity similar to that of the eye.
microprojectorA miniature projecting device designed to enhance and reproduce the image generated by a smaller image-forming instrument....
Ultraviolet-CUltraviolet-C (UV-C) refers to a specific range of ultraviolet radiation with shorter wavelengths than those of visible...
fluorescent screenA fluorescent screen refers to a phosphorescent or fluorescent-coated surface that emits visible light when exposed to other...
photovoltaicPhotovoltaic (PV) refers to a technology that converts sunlight directly into electricity using semiconductors. The term...
infrared light-emitting diodeAn infrared light-emitting diode (IR LED) is a semiconductor device that emits infrared light when an electric current...
lens mountThe metal tube that maintains the optical components of a lens in proper relationship. Some lenses are mounted in metal...
laser speckleSparkling granular pattern that is observed when an object diffusely reflects coincident laser light. Speckle appears as an...
radiographAn x-ray or radium photograph illustrating the nonuniform density of the structure that the rays penetrate.
coordinate measuring microscopeAn instrument used to measure the coordinates of a point on an object such as a photographic plate.
optical multimeterAn instrument that measures several optical parameters, such as optical power and wavelength, with a single measurement...
hydrogenated amorphous siliconA photoreceptor material used in solar cells and in drums for laser printers and high-speed copiers because of its high...
macrophotographythe photography of very close, and typically small objects with a magnification of approximately 1:1
chronophotographyThe photographic recording of an action by taking a series of still pictures at regular intervals throughout the action.
adaptive opticsAdaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of...
magnonA magnon is a quasiparticle representing a quantized spin wave in a magnetic material. In other words, it is a collective...
synthetic interferometric imageAn imaging technique in which an object moving through an interference field formed in space scatters light and is spatially...
photoelectric colorimetryThe measurement and analysis of color using a photoelectric instrument having three filters with broad spectrum bands.
whispering gallery modeWhispering gallery mode (WGM) refers to a phenomenon in wave physics, particularly in optics, where waves, such as light or...
photosurfaceThe surface from which electrons are ejected by the incidence and absorption of photons.
motion picture cameraA camera equipped with a lens and a long length of perforated film, the latter being moved intermittently between exposures...
oximeterA device that uses a photoelectric cell to determine the level of oxygenation in the blood.
positron emission tomographyA medical imaging device that uses a ring of crystal/photomultiplier tube assemblies encircling the patient to detect gamma...
inverse square lawThe law stating that the illuminance (or irradiance) from a point source varies as the inverse square of the distance...
wide-angle distortionA common aberration in lenses covering large fields of view; it results in images of objects near the edge of the field...
optical headIn compact disc and CD-ROM technology, the portion of the drive that projects the laser light onto the surface of the media...
nanotubeA nanotube, also known as a nanotubule or simply a tube-like structure, is a nanoscale cylindrical structure composed of...
Monte Carlo simulationSimulation of radiative transfer in which each photon is generated by a source and its path through the medium is...
Cooke objectiveA telephoto lens form noted for its lack of distortion.
soft radiationTerm applied to radiation composed of particles or photons that will not easily penetrate a material because of their low...
gain-bandwidth productIn an avalanche photodiode, the gain multiplied by the signal frequency in MHz.
Newtonian telescopeA telescope with a concave paraboloidal objective mirror and a small plane (diagonal) mirror that reflects rays from the...
phototubeAn electron tube having a photocathode for the emission of a photoelectric current.
near-field regionThe area closest to an aperture or source where the diffraction pattern differs substantially from that observed at an...
prism powerThe power, expressed in prism diopters, that is the linear displacement, in centimeters, produced by the prism one meter...
photonA quantum of electromagnetic energy of a single mode; i.e., a single wavelength, direction and polarization. As a unit of...
instantaneous field of viewInstantaneous field of view (iFOV) is a term commonly used in the context of remote sensing, imaging systems, and optical...
halo1. The faintly hued ring that is seen to surround a light source viewed through fog or light clouds. The size of scattering...
pixel binningPixel binning, also known as pixel merging or pixel combining, is a technique used in digital imaging and camera technology....
autoradiographyThe photographic recording of the distribution and location of radioactive substances found in a specimen. The record formed...
x-ray filmA film or plate that is usually coated on both sides with a very fast emulsion that is sensitive to x-rays, and used to...
fanA set of rays through a lens originating at a common point and contained in one plane.
film scanningThe process by which the light from the images of photographic film is encoded into electrical signals for video...
optical tableAn optical table, also known as an optical bench or an optical breadboard, is a specialized platform used in optics...
image comparisonA method used in imaging to detect subtle differences between two apparently similar pictures. It can be achieved by...
microspectrophotometerA specialized spectrophotometer for use through a microscope on very small areas of an object.
epoxyCommon name for a variety of adhesives used for lens bonding, fiber optic splicing and other photonics applications. The...
speckle metrologyRefers to the variety of techniques that use the interference pattern produced by laser light diffusely reflected by an...
Petzval surfaceA paraboloidal surface on which the image is located when there is no astigmatism.
machine vision systemA machine vision system is an integrated combination of hardware and software components designed to capture, process, and...
laser velocimeterA system that uses a continuous-wave laser to measure the velocity of an object by focusing the laser beam on the object,...
photosensitizerA substance that increases a material's sensitivity to electromagnetic irradiation. In photodynamic therapy, a drug used to...
photoelectric spectrophotometerA system that consists of a spectrophotometer with a photoelectric detector for measurement of radiant energy.
channel impedanceThe parallel resistance and capacitance appearing between the active guard ring junctions in a silicon photodiode.
advanced photon sourceAn accelerator at the Argonne National Laboratory, providing powerful x-ray beams for materials research applications.
contact fluorographyA fluorographic method whereby the sensitive photographic medium is pressed against a fluorescent screen to form a visible...
photon drag effectThe induction of an electric field in a semiconductor by an incident laser beam. The technique has rapid response time at...
Maksutov correctorA thick meniscus lens arranged concentric with the center of curvature of a spherical mirror to produce an image free of...
Verdet constantA factor of an equation of the Faraday effect, which is the rotation of the plane of light polarization by transparent...
photoelectron microscopySurface analysis by means of photon induced electron emission. PEM methods provide high lateral resolution of the observed...
three-level laserA laser having a material, such as ruby, that has an energy state structure of three levels: the ground state (1) wherein...
retroreflectionRetroreflection is a phenomenon in optics where light is reflected back toward its source, typically in a direction nearly...
bacteriorhodopsinA light-harvesting protein found in the purple membrane of a micro-organism called Halobacterium halobium. The protein...
quantum wellA quantum well is a structure in quantum mechanics that confines particles, such as electrons or holes, in one spatial...
tangential distortionOptical aberration such that image magnification varies with ray distance from the optical axis in a radial distortion.
electron microscopeA device utilizing an electron beam for the observation and recording of submicroscopic samples with the aid of photographic...
projection x-ray microscopeA microscope that uses an extremely fine x-ray focal point to produce an enlarged photographic image of a sample. Also known...
photoelectronElectron released in photoelectric activity.
infrared photoconductorA photoconductor that demonstrates increased conductivity during its exposure to infrared radiation.
III-V materialIn semiconductor physics and materials science, the term "III-V materials" refers to compounds composed of elements from...
etalonAn etalon is an optical device that consists of two parallel reflecting surfaces separated by a precise and known distance....
photoreactive agentParticipates in a reaction only in the presence of light and radiant energy. Besides 3D printing, photoreactive agents also...
ultrahigh-speed photographyPhotographic recording of rapid events at a rate exceeding 106 frames per second.
color scannerAn instrument that uses a beam of light to scan a color transparency, and three differently filtered photosensors to record...
riez photodiodeA photodiode having a conducting grid that covers the surface of the photodiode junction and intercepts and wastes some of...
laser opticsLaser optics refers to a broad category of optical components and systems designed for manipulating and controlling laser...
laser cavityA laser cavity, also known as an optical cavity or resonator, is a fundamental component of a laser system. It is a confined...
endoscopic photographyThe photographing of objects within generally inaccessible areas using endoscopes with camera attachments.
cathode radiant sensitivityCathode radiant sensitivity refers to the ability of a photocathode to convert incident radiant energy, typically in the...
silver halide emulsionAn emulsion in which grains of the photosensitive material silver halide are deposited. Each grain, when exposed to light,...
optical assemblyAn optical assembly refers to a collection of optical components that are carefully arranged and aligned to perform a...
photometric filter
macrophotographThe photographic recordformed in macrophotography in which the size of the small nearby object at theimage plane is the same...
transducerA transducer is a device or component that converts one form of energy into another. It is commonly used in various fields,...
lead selenide cellA thin-film photoconductive cell that is sensitive to the infrared region. The photosensitive material of the cell is...
thermal dissociationA technique for detecting free radicals by their electronic spectra. The material to be studied is placed in a...
phototheodoliteA camera equipped with angular scales in altitude and azimuth. The scale readings are imprinted on the film when an exposure...
spectrophotometryStudy of the reflection or transmission properties of specimens as a function of wavelength.
plasmonicsPlasmonics is a field of science and technology that focuses on the interaction between electromagnetic radiation and free...
photopolymerizationA process in which a mixture of one or more monomers, plus a catalyst, polymerize under exposure to light radiation....
integration timeIntegration time, in the context of optics, imaging systems, and sensor technology, refers to the duration over which a...
opticsOptics is the branch of physics that studies the behavior and properties of light, including its interactions with matter...
rotary cameraA camera system used for microphotography that has a structure, such as a cylinder or surveyor belt, to rotate the documents...
stereolithographyA method of creating real three-dimensional models by using lasers driven by CAD software. In contrast to the normal...
electron-beam lithography systemAn electron-beam lithography (EBL) system is a sophisticated nanofabrication tool used in the semiconductor industry and...
variable-focus condenserAn Abbe condenser in which the upper lens element is fixed. The lower lens may focus the illumination between the elements...
divided slit scanA scanning technique in optical character recognition in which an array of photocells is used to scan each character to...
microfilm equipmentTwo essential pieces of equipment used in connection with the microfilming process: a camera capable of producing, on film,...
connectorHardware installed on fiber cable ends to provide cable attachment to a transmitter, receiver or other cable. Usually a...
photoacoustic gas cellA device for measuring absorption coefficients in which a confined, nonabsorbing gas fills the space inside the cell between...
photon couplingThe coupling of two circuits by the use of a light pipe through which photons are transmitted.
photomacrography
double refractionThe separation of unpolarized light into two plane-polarized elements by a doubly refracting crystal. When a crystal, such...
electron-beam film scanningThe method by which photographic film is scanned by an electron beam. One technique uses the uniform light of a television...
photomagnetic effectThe direct influence of light on the magnetic susceptibility of particular materials.
field1. In raster scan television, one of the two scans that are interlaced to make up a frame. 2. See field of view.
photoionizationThe ionization that occurs in gas affected by the action of radiation quanta.
photoelectromotive forceThe force that stimulates the emission of an electrical current when photovoltaic action creates a potential difference...
gas phototubeA phototube having increased response due to the addition of a quantity of gas.
serpentine bend mode filterA device used in measuring attenuation in optical fiber. The loss caused by the bends in a short reference length of fiber...
thyratronAn arc discharge tube having a grid that is used to start the discharge through an atmosphere of inert gas or vapor at low...
orthographic cameraA camera designed with a telecentric optical system and a narrow field of view; the telecentric optical system (placement of...
Koenig-Martens spectrophotometerA visual, single-unit spectrophotometer with a biprism and a Wollaston prism. The Wollaston prism polarizes coincident...
camera reductionThe use of the photographic process to produce precision copies of an original image that are many times smaller in size....
Fizeau interferometerA type of interferometer noted for producing narrow multiple-beam interference fringes. As a result, when compared with the...
polygon mirrorA rotating component with a series of flat reflective surfaces around the perimeter that is used in scanning systems to...
electrostatic tape cameraA camera that records its images electrostatically on plastic tape; used in situations where radiation would have an adverse...
inverse Compton effectThe interaction between a photon and an energetic electron, caused by collision, that transfers energy from the electron to...
near-infrared spectrometerA near-infrared (NIR) spectrometer is an analytical instrument used to measure the absorption, transmission, or reflection...
microring resonatorA microring resonator is a compact optical device that utilizes the resonant behavior of light within a small ring-shaped...
dual-wavelength spectrophotometrySpectrophotometry in which radiation of two separate wavelengths, usually one in an absorption band and the other not, pass...
flash photolysisA spectroscopic technique used in the detection of free radicals by virtue of their electronic spectra. In this method, an...
Casimir forceThe Casimir force is a quantum phenomenon that results in an attractive force between two closely spaced uncharged...
brightness resolutionThe degree to which a pixel in a digital image represents the analog brightness of the corresponding point in the original...
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...
reflectionReturn of radiation by a surface, without change in wavelength. The reflection may be specular, from a smooth surface;...
slide projectorAn optical projection device designed to project positive color transparencies onto a screen for viewing.
photographic sound recorderA system in which the electrical signal embedded within an audio input signal is converted to a modulated light pattern and...
scanning electron microscopeAn electron microscope that uses a beam of electrons -- accelerated to high energy and focused on the sample -- to scan the...
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,...
Poisson shot noiseA stationary noise that occurs for visible light photodetection when a steady light source, such as a heterodyne reference...
trichromacyThe basis of color vision in the human eye. Three types of cones have been identified, each having a unique spectral...
Brewster's angleFor light incident on a plane boundary between two regions having different refractive indices, the angle of incidence at...
silicon photodiodeA silicon photodiode is a semiconductor device that converts light into an electrical current. It is a type of photodetector...
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...
Pockels cellA device containing an electro-optic crystal and using the Pockels effect. A voltage applied across the crystal generates...
photoradiation therapy
open-dish methodA measurement method for reflectance by gas ionization in which light passes through a vapor before and after reflection....
photodischarge spectroscopyA spectroscopic process that detects and analyzes the discharge from an extrinsic surface with less than bandgap light. This...
astronomical mirrorAn astronomical mirror, also known as a telescope mirror or primary mirror, is a key component of a reflecting telescope. It...
quantum detectorA photodetector in which an electrical charge is produced when incident photons change electrons within the detecting...
latensificationA short term for latent image intensification, a process much like hypersensitizing in photography, but used after exposure...
image orthiconA camera tube widely used in television broadcasting. It consists of three sections within a single vacuum envelope. 1. A...
skew angleThe angle at which photoelectric sensors are aligned to prevent light from being reflected back to the sensor from the...
colorimetric photometerA photometer that uses a set of color filters to measure the intensity of light in various regions of the spectrum.
astronomical telescopeAn astronomical telescope is a type of optical instrument designed to gather and magnify light from distant celestial...
laser-light-scattering photometerA scattering photometer using scattered light in the solid angle 4.51+0 19° with respect to the forward direction, and...
photoemulsionIn photolithography, an opaque material used in masks that has a lower optical density and grainier composition than chrome.
photon noise
fiber-coupled photoconductive antennaA fiber-coupled photoconductive antenna (FCPA) is a type of optoelectronic device that combines a photoconductive antenna...
electron microradiographyThe photographic recording, and later enlarging, of very thin specimens, using an electron beam to form the image.
heterochromatic photometryLight measurement by comparison of the luminances of unlike chromaticities.
back focal lengthThe distance from the final optic within a system to the rear image point of the system. See focal length.
optical memory1. The direct storage of data as bits in memory using optical systems and properties. The memory makes use of a laser beam...
digital cameraA digital camera is a device that captures and records still images or video in digital format. Unlike traditional film...
infrared image tubeAn image converter that produces a visible image based on the infrared emittance of the object. The infrared energy is...
latticeIn photonics, a lattice refers to a periodic arrangement of optical elements or structures, often on a microscopic or...
diffractive opticsOptical elements that use diffraction to control wavefronts. Diffractive optical elements include diffraction gratings,...
single molecule localization microscopySingle molecule localization microscopy (SMLM) is a group of super-resolution microscopy techniques that surpass the...
telephotography1. A method of photographing distant objects with a lens of long focal length. 2. The reproduction of photographs over a...
photomicrographyThe use of a microscope in photographing objects. A device for photomicrography includes a light source, microscope and...
thermal photography
cadmium sulfide cellA photoconductive cell having cadmium sulfide as its photoconducting material for the production of a very high dark-light...
channel electron multiplierA photoelectric detector consisting of a glass tube internally coated with a low conductance material. Voltage applied along...
lay lengthIn a fiber optic cable, the longitudinal length required for the transmission media, wrapped around a central member, to...
Raman effectWhen light is transmitted through matter, part of the light is scattered in random directions. A small part of the scattered...
telecentric lensThere are three types of telecentric lenses:
-Image-space telecentric lenses are those in which the aperture stop is...
photoglow tubeA particular type of phototube having increased sensitivity as a result of the glow initiated by light incident to the...
infrared instrumentAny of the photoelectric and thermal detectors, spectrographs and monochromators, thermographs, scanners, amplifier tubes,...
chromatic aberrationChromatic aberration is an optical phenomenon that occurs when different wavelengths (colors) of light are refracted by a...
photopumpingThe use of light to initiate the lasing process. See optical pumping.
photoacoustic effectGeneration of an acoustical signal by a sample exposed to modulated light.
irisThe adjustable membrane located just in front of the crystalline lens within the eye. The iris gives the eye its color. See...
sensitometerAn instrument for determining the sensitivity of a photographic film to light. The film is given either a stepped exposure...
fluoro-immunosensorA fiber optic device that uses a HeNe laser, beamsplitter, monochromator and photomultiplier to detect trace levels of...
phototransistorA solid-state device similar to an ordinary transistor except that incident light on the PN junctions regulates the response...
ultraviolet reflectanceUltraviolet reflectance refers to the ability of a material or surface to reflect UV light. Ultraviolet light is...
axisA straight line, real or imaginary, passing through a body and indicating its center; a line so positioned that various...
stimulated Brillouin scatteringIn Stimulated Brillouin Scattering (SBS), an incident photon (usually laser light) interacts with acoustic phonons in a...
light diffusionLight diffusion refers to the process by which light is scattered or spread out in various directions as it interacts with a...
pyroelectric infrared detectorUnlike the thermocouple or bolometer, the pyroelectric infrared detector is a current source with an output proportional to...
cameraA light-tight box that receives light from an object or scene and focuses it to form an image on a light-sensitive material...
microflashAn extremely short, high intensity electronic flash of light, having a duration of about 1 x 10-6 s, used in photographing...
printerA photographic enlarger with a fixed negative plane and a fixed paper plane, often using a roll of paper that is advanced...
lithographyLithography is a key process used in microfabrication and semiconductor manufacturing to create intricate patterns on the...
photocathode luminous sensitivityThe responsivity of a photocathode to luminous energy equal to the ratio of the photoelectric emission to the incident...
CCD image sensorA CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images...
direct-vision prismAn assembly of multiple prisms that disperses incident light into its spectral components without deviating light at the...
Josephson effectCharacteristic of radiation detectors that produce energy that is similar to the energy of superconductive gaps when...
copper oxide photocellAn early type of nonvacuum photocell consisting of a layer of copper oxide on a metallic substrate, with a thin transparent...
flame spectrophotometryThe study of the reflection or transmission properties of specimens as a function of wavelength after they have been excited...
photoconductive filmA film of material that exhibits varying conductivity based upon its absorption of varying amounts of photon radiation.
binocularDesignating any instrument in which both eyes can be used to view the image to achieve a stereoscopic effect, or merely to...
quantum entanglementQuantum entanglement is a phenomenon in quantum mechanics where two or more particles become correlated to such an extent...
multileg lightguideA fiber optic bundle split along its length with the ends of the fibers extending separately to illuminate different points...
aerial photogrammetryThe application of aerial photographs as a means of measurement in map making and surveying.
optoacousticOptoacoustic, or photoacoustic, refers to a phenomenon and related techniques that involve the generation of acoustic waves...
dust counterAn instrument that uses a photoelectric system to determine the size and volume of dust particles in a given unit of air.
flying spot scannerA device used to scan, with a small, intensely bright spot, portions of a picture surface and to transform the original...
quantum key distributionQuantum key distribution (QKD) is a method of secure communication that utilizes principles from quantum mechanics to...
two-photon fluorescenceThis results from the simultaneous absorption of two photons, each having half the energy needed for excitation and...
critical angleThe least angle of incidence at which total internal reflection takes place. The angle of incidence in a denser medium, at...
photoimmunotherapyPhotoimmunotherapy (PIT) is a medical treatment approach that combines elements of phototherapy and immunotherapy to target...
monochromatic lightLight consisting of a single wavelength or a very narrow band of wavelengths.
linear image sensorA linear image sensor is a type of solid-state electronic device used to capture and convert light into electrical signals....
vignettingIn an optical system, the gradual reduction of image illuminance as the off-axis angle increases, resulting from limitations...
holographic interferometryThe interferometric analysis of a complex object by utilizing the three-dimensional hologram. By causing a laser beam to...
isochromatic lines1. Lines of the same color. 2. A term used in photoelastic stress analysis to refer to the interference fringes produced in...
cesium 134An isotope of cesium that emits negative beta particles and has a half-life of 2.19 years; its applications include...
crystalline axesThe axes of symmetry in a crystal structure. See also biaxial crystal; uniaxial crystal.
absorption peakAn absorption peak refers to a sharp increase or spike in the absorption of electromagnetic radiation at a particular...
air-to-ground phototransmission systemA category of systems designed to communicate a photo taken from the air (e.g., aircraft, balloon, satellite) to a ground...
rapid access systemA photographic camera and processing system used to form a usable record of the subject in a short time, usually a few...
phase maskIn optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it....
adjacency effectWith respect to photography, the change in the density-exposure relations, for small details of the photographic image, that...
chemosphereAlso known as mesosphere. A level of the atmosphere, extending from the stratosphere to the ionosphere, that is noted for...
optical design softwareOptical design software refers to specialized computer programs used by optical engineers, physicists, and designers to...
reticulationThe formation of a distinct, irregular surface pattern on a photographic emulsion due to differential swelling of the...
photoelasticIn optics, the double refraction that is produced when stress is applied to a transparent material. Plastics, which are...
glossmeterA photometer for measuring gloss by comparing the specular reflectance to that from a perfect specular reflector.
eye test apparatusInstruments used by ophthalmologists and optometrists to study the eye. There are, for instance, the ophthalmoscope to...
Schumann plateA specific type of photographic plate designed with only a small amount of gelatin to function in the extreme ultraviolet...
gas photocellA photoemissive cell having an inert gas added to its envelope. Subsequent ionization of the gas increases the responsivity...
disc colorimeterA colorimeter using a spinning disc made of different colored sections for colorimetric analysis.
surface reflectionAlso known as Fresnel reflection. That portion of the incident radiation that is reflected from the surface of a refractive...
multicolor hologramA hologram formed by reconstruction of multicolor wavefronts. The system used to produce the hologram is designed to combine...
ablative photodecompositionAblation applied to polymers and chemical solids. Process of material removal that minimizes edge damage but will not heat...
intrinsic photoemissionThe photoemission that would occur if a crystal were pure and its structure perfect.
photonic integrated circuitA photonic integrated circuit (PIC) is a compact and integrated device that incorporates multiple photonic components and...
color facsimile transmissionThe transmission of a color photograph by separating the colors into varying intensities of red, blue and green, and then...
thermogramAlso known as analog thermogram. The resultant photograph, illustrating, in tones ranging from black to white, the spatial...
delay timeThe interval between direction of signal to a light-emitting diode and attainment of 10 percent output current in the...
phononA phonon is a quantum of vibrational energy associated with the periodic motion of atoms or molecules in a crystalline...
degree of coherenceA quantitative measurement of the coherence of a light source; equal to the visibility (V) of the fringes of a two-beam...
wafer tubeAn image intensifier tube in which the photocathode and the output of the microchannel plate are proximity-focused on the...
resonance radiationThat radiation emitted by an atom or molecule that has the same frequency as that of an incident particle; e.g., a photon....
holocameraA camera system used to form a high-precision hologram of the subject on a photographic plate. It contains a high-power...
chronophotographThe continuous record containing the series of pictures formed by chronophotographic methods.
CMOS cameraA CMOS camera refers to an imaging device that employs a complementary metal-oxide-semiconductor (CMOS) image sensor to...
multianode microchannel array detectorA photon-counting instrument for use in both space-borne and ground-based photometric and spectroscopic instrumentation....
panoramic cameraA camera designed to form a continuous record of an expansive section of the horizon. The typical panoramic camera is...
depth of focusThe range of image distances that corresponds to the range of object distances covered by the depth of field.
optical density (photographic)The transmittance of a point on a photographic negative equal to the log to the base 10 of the reciprocal of the...
spatial resolutionSpatial resolution refers to the level of detail or granularity in an image or a spatial dataset. It is a measure of the...
thermal recordingA term referring to various processes for forming visible images outside of a camera to be photographed on ordinary film....
illuminometerA photometric instrument used to measure the illumination falling on a surface. It may be photoelectric or visual.
anomalous photoconductivityA spectral phenomenon in which the degree of the photoresponse of an illuminated semiconductor is determined by the...
nonlinear scatteringDirect conversion of a photon from one wavelength to a lower energy photon of another wavelength(s) due to inelastic...
secondary emission photocell
photon drag detectorAn infrared detector in which radiation passes through a doped germanium crystal, creating a voltage drop that can be...
standing waveThe combination of two waves having the same frequency and amplitude and traveling in opposite directions. Standing waves...
grown-junction photocellA photodiode that has been designed so that the bar of semiconductor material has a PN junction perpendicular to its length...
isodensitiesThe points on a photographic negative that are of equal density.
retrofocus lensAlso known as reversed telephoto lens. A lens consisting of an ordinary objective with a negative component near its front...
biplanar image tubeAlso called proximity focus image intensifier. A compact image intensifier that utilizes a microchannel plate...
phase matchingPhase matching is a crucial concept in the field of optics, particularly in nonlinear optics and the generation of coherent...
aerocartographyThe creation of topographical maps and charts from a stereographic record produced through the overlapping of consecutive...
emulsion speedThe sensitivity of a photographic emulsion when exposed to light, provided that the film is developed through a standard...
electrophotographyThe photographic recording of an image formed by the alteration in electrical properties of the sensitive materials and...
nominal ocular hazard distanceThe calculated normal distance from a photon source at which harmful interaction with the incident light will occur....
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...
photographic photometryA form of photometric measurement, often used with light sources that are transparent or fluctuating, in which a...
ultraviolet spectrometerA spectrophotometer designed for use in the 200- to 380-nm range of the electromagnetic spectrum and equipped with a...
transitionThe process whereby a quantum mechanical system alters from one energy level to another. During this process, energy is...
Winston coneSpecified curved optic intended for maximum collection of light, including off-axis rays, before leaving the exit aperture.
unmanned aerial vehicleAn unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot onboard. UAVs are remotely...
photoconductor contactMaterial used to integrate photoconductors into electro-optical systems. It should provide low resistance to the flow of...
Huygenian eyepieceAn ocular having two planoconvex lenses that are formed from similar glass and that are separated by a space equal to half...
microbubble resonatorA microbubble resonator is a device used in photonics and optical physics for the precise manipulation of light waves. It...
neodymium:YAGLiterally, neodymium:yttrium-aluminum-garnet. A cylindrical rod of yttrium-aluminum-garnet doped with neodymium that is the...
evaporagraphA sensor generally used for infrared imaging. It consists of two chambers separated by a thin, blackened membrane. An...
medical lasersMedical lasers are devices that produce intense beams of light with specific characteristics and properties, which are used...
transparencyAn image affixed to a transparent photographic film or plate by photographic, printing or chemical methods. It may be viewed...
time-correlated single photon countingTime-correlated single photon counting (TCSPC) is a technique used in photon counting applications, particularly in the...
bandgapIn semiconductor physics, the term bandgap refers to the energy range in a material where no electronic states are allowed....
birefringenceBirefringence is an optical property of certain materials that causes them to exhibit different refractive indices for light...
autofluorescenceAutofluorescence refers to the natural emission of fluorescence exhibited by certain biological structures or molecules when...
second-harmonic generation microscopyA nonlinear label-free imaging technique commonly used during surgical procedures for the visualization of collagen fibers...
digital optical processingThe scanning of photographs or transparencies of images, either by a vidicon camera or flying spot scanner, for the...
mosaicOne surface of a nonconducting plate that is coated with many minute particles of photoemissive material that are insulated...
excimer laserAn excimer laser is a type of ultraviolet laser that emits short pulses of light in the ultraviolet spectrum. The term...
optical tweezersOptical tweezers refer to a scientific instrument that uses the pressure of laser light to trap and manipulate microscopic...
fluorescence lifetimeFluorescence lifetime refers to the average time it takes for a fluorophore, a molecule that absorbs light at one wavelength...
three-photon microscopyThree-photon microscopy is an advanced imaging technique that belongs to the family of multi-photon microscopy methods. It...
card readerA system that generally uses a photodetector to decode punched cards for information, or for input to a computer, by sensing...
optical cements and adhesiveOptical cements and adhesives are specialized materials used in the assembly and bonding of optical components in optical...
attosecond photonics sourcesAttosecond photonics sources refer to devices or systems that generate extremely short pulses of light on the order of...
photoconductive effectThe alteration of electric conductivity produced by the absorption of varying amounts of radiation composed of photons.
Raman spectroscopyRaman spectroscopy is a technique used in analytical chemistry and physics to study vibrational, rotational, and other...
insertion lossThe total optical power loss caused by the insertion of an optical component such as a connector, splice or coupler into a...
iconoscopeA camera tube that employs a high-velocity electron beam to scan a photoemissive mosaic and to store electrical charge...
telephoto ratioIn a telephoto lens, the ratio of the overall length to the focal length of the lens. It is generally about 0.8 to 0.9 in...
reflectance spectrophotometerAn instrument that spectrally analyzes the flux reflected from a material. The reflected flux may be total, diffuse or...
modified chemical vapor depositionModified chemical vapor deposition (MCVD) is a technique used in the fabrication of optical fibers. It is a specialized form...
aperture stopA physical constraint, often a lens retainer, that limits the diameter of the axial light bundle allowed to pass through a...
fullerenesMolecules composed entirely of carbon, in the form of a hollow sphere, ellipsoid or tube. Also called buckyballs....
optical character readerA photosensitive device used to optically scan and read character data (numbers, letters etc.) and input this data into a...
population inversionThe condition in which there are more atomic systems in the upper of two energy levels than in the lower, so stimulated...
Mangin mirrorA double-surfaced catadioptric spherical mirror whose spherical first surface consists of a negative meniscus (concave) lens...
field effect transistor photodetectorA photodetector employing photoregeneration of carriers in the channel region of an FET structure to provide photodetection...
photoelectric controlThe control of an instrument or electrical circuit by the current produced by varying radiation incident to a photoelectric...
autopositiveAny photographic medium that, when chemically developed, produces an exact photographic reproduction of the original.
free-space opticsFree-space optics (FSO), also known as optical wireless communication or optical wireless networking, refers to the...
spectroscopySpectroscopy is a technique used in the study of interactions between matter and electromagnetic radiation. It involves...
formateA salt of formic acid that can be used to enhance the photosensitivity of silver halide crystals.
photomultiplier tubeA photomultiplier tube (PMT) is a highly sensitive vacuum tube that detects and amplifies low levels of light. It is widely...
frame cameraA high-speed cine camera that produces discrete frames of a continuous event as opposed to the flow photographic record of a...
intrinsic detectorA photodetector composed of a photoconductive material that, when exposed to radiation, conducts without the aid of added...
MEMS fiber optic switchA MEMS fiber optic switch is a microelectromechanical system (MEMS) device designed to selectively route optical signals...
convergent beam sensing modeA type of photoelectric proximity mode sensing incorporating a lens system to focus the light from the emitter in a small,...
flash photographic density filterA filter, partially opaque to near-ultraviolet, visible and infrared radiation, that may be made by exposing and processing...
stop-motion cameraA motion-picture camera that can be advanced one frame at a time, either randomly or at set intervals. Used in animation and...
thallofide cellA photoconductive cell that uses thallium oxysulfide as the light-sensitive medium.
microheterogeneous systemsExtremely small organic and inorganic systems of molecules within a substance. In general, systems are colloidal size in...
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...
Kerr cellA cell filled with a transparent material that, when placed in a strong electrical field, exhibits double refraction. Since...
halation1. In a cathode-ray tube, the glow surrounding a bright spot that appears on the fluorescent screen as the result of the...
Wadsworth mountingA system used for gratings that consists of a concave mirror, a grating and a plate holder mounted normal to the grating to...
optical modulatorA multilayered thin-film device used to modulate transmitted light in integrated photonic circuits.
Eberhard effectObserved phenomenon of a small developed image with higher density than a larger image because of variation in photographic...
cold atomCold atoms refer to atoms that have been cooled to extremely low temperatures, typically in the microkelvin (µK) to...
photometerA device used to compare the luminous intensities of two sources by comparing the illuminance they produce.
acoustophotorefractive effectThe change in refractive index that occurs as acoustic vibrations are transmitted through an optical material.The index...
photosensitivityThat property of a material indicating that it will react when exposed to light energy.
brightfieldBrightfield refers to a type of microscopy and imaging technique in which the specimen is illuminated with a white light...
chromosphereA layer between the corona and the photosphere of the sun; its emission is overwhelmed by light emitted by the underlying,...
blue diode laserA blue diode laser is a type of semiconductor laser that emits light in the blue wavelength range of the electromagnetic...
photopolymerA polymer produced as a result of photochemical processes.
reagentA reagent is a substance or compound that is used in a chemical reaction to bring about a specific transformation or to...
photoemissive effect
microficheA small card (10 x 15 cm) that has been treated with a photographic emulsion to record and store the microimages of...
photonic crystal surface-emitting laserPCSEL stands for "photonic crystal surface-emitting laser." It refers to a type of laser diode that emits light from its...
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...
cathode-ray tubeA vacuum tube with an electron gun at one end and a fluorescent screen at the other. Electrons emitted from a heated...
superelastic collisionObserved phenomenon in laser pulses in which a large number of excited electrons are created and in which multiphoton...
objective gratingA coarse diffraction grating that is used to form a scale of intensities to determine the relative magnitudes of stars. The...
photoelectric relayA relay that opens or closes an electrical circuit depending on the intensity of the light incident to a photoelectric...
causticA surface that envelops a bundle of rays or bundle of normals to the wave surface. It may be observed as a hollow, luminous...
Doppler-spread imagingAn imaging process, similar to specific Doppler mapping radar techniques, that utilizes a laser, an optical imaging system,...
solarization1. The reduction in the developable density of a photographic emulsion that has been extremely overexposed. 2. In a laser...
dark boxA lightproof box used for storing photosensitive materials.
Hartmann testA test for spherical aberration, coma or astigmatism in which incident rays from a point source are isolated by small holes...
focal lengthThe focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or...
microfilm cameraA camera used to reduce originals onto film for easy storage. There are two basic types: one in which the film is fixed...
photochemicalThe term photochemical pertains to chemical processes or reactions that are initiated or influenced by the absorption of...
long-pass filterA long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or...
lightElectromagnetic radiation detectable by the eye, ranging in wavelength from about 400 to 750 nm. In photonic applications...
orange peelIn the context of imaging, particularly digital imaging and printing, "orange peel" refers to a texture or visual distortion...
photoacoustic calorimetryPeriodic interruptions of a light beam incident on an absorbing medium that produce heat, expansion and acoustic wave...
diamond turningDiamond turning, also known as diamond machining or diamond cutting, is a precision machining process used to produce...
optoelectronic transistorA transistor that uses an electro-luminescent source, a transparent base and a photoelectric collector.
machine vision lensA machine vision lens is a specialized optical lens designed for use in machine vision systems, which are used for automated...
photosphereThe apparent surface of the sun or a star from which light appears to radiate.
arcuate displacementDisplacement in a direction perpendicular to that of the intended displacement, as in a translation stage with simple...
photosynthetically active radiationPhotosynthetically active radiation (PAR) is the 400- to 700-nm region (visible light) of the electromagnetic spectrum that...
xenon arc photocoagulatorAn instrument for eye surgery that directs intense xenon arc light through the transparent cornea lens to the retina where...
Rayleigh rangeIn the region of a Gaussian beam focus by a diffraction-limited lens, it is the axial distance from the point of minimum...
incoherent holographyThe production of holograms initially from either conventional photographs or incoherent optical equipment.
vacuum ultraviolet detectorA device that serves to detect the presence of vacuum ultraviolet radiation. It may be photographic film, a thermopile, ion...
polarization photometerA photometer having a pair of Nicol prisms introduced into the beam from the brighter of two sources to be compared. Turning...
opposition effectAlso referred to as the opposition surge, the opposition effect is a photometric phenomenon in which a rough retroreflective...
magneto-optic shutterA type of high-speed photographic shutter that uses Faraday rotation to produce exposure times as fast as 1 microsecond. It...
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...
photochromatic intervalThe discrepancy between the absolute luminance threshold and the photochromatic threshold.
high-density storageExtensive data storage in the form of bits, with the use of high-resolution photographic materials and optics, and generally...
photon tunneling microscopeAn instrument in which visible light beyond the critical angle from a metallurgical microscope is focused on a reference...
TO packageHousing that resembles a small metal can for a semiconductor component, photodetector or similar device.
filter factorThe necessary increase of a photograph's exposure time as the result of the additional absorption of light by the filter...
photon jetA photon jet is a narrow, highly collimated beam of light that is formed when light interacts with small dielectric...
color photographic filmFilm that produces color negatives or transparencies by the use of three emulsions, one coated over the other, that are each...
photoconductive antennaPhotoconductive antenna (PCA) is a semiconductor element that generates or detects high-frequency electromagnetic signals....
radiometerA device used to measure the intensity of radiant energy.
fluorescence decay systemA device, also called a fluorescence lifetime instrument, that measures decay curves of fluorescing samples. It generally...
photocurrentThe current that flows through a photosensitive device, such as a photodiode, as the result of exposure to radiant power.
retroreflectorA retroreflector is an optical device or structure that reflects incident light or electromagnetic waves back to their...
selenium cellA photoconductive cell consisting of a layer of selenium on a substrate whose electrical resistance varies with the...
hyperspectral imaging cameraA hyperspectral imaging camera is a sophisticated imaging device capable of capturing and processing data across a wide...
vertical-cavity laser diodeA type of surface-emitting laser diode that uses dielectric mirrors to produce surface emission. The laser cavity is...
optical fluorographyThe fluorographic method whereby the visible image (as opposed to the x-ray image) is photographed by mounting a camera in...
hematoporphyrin derivativeA material used in photodynamic therapy that is retained selectively by tumor tissue when injected into the body; it then...
polarizationPolarization refers to the orientation of oscillations in a transverse wave, such as light waves, radio waves, or other...
vidiconA small television tube originally developed for closed-circuit television. It is about 1 inch in diameter and 5 inches...
cylindrical lensA cylindrical lens is an optical component that has different curvatures along its two orthogonal axes, resulting in a shape...
electronic photometer
slow-scan televisionA television system that uses a slow rate of horizontal scanning to increase its reproduction and transmittance accuracy of...
optical gateAn optical gate typically refers to a device or system that controls the transmission of light, allowing it to pass through...
fiber-coupled LEDA fiber-coupled LED (light-emitting diode) refers to an LED device that is optically coupled to an optical fiber for the...
attosecond-pump attosecond-probe spectroscopyAttosecond-pump attosecond-probe spectroscopy (APAP) is an advanced technique in ultrafast spectroscopy that allows...
photoconductorA light-sensitive resistor in which resistance decreases with increase in light intensity when illuminated. The device...
meniscus lensA lens that has one convex surface and the other concave.
equivalent air pathWhen a block of glass (prism, window, filter, etc.) is placed into a converging light bundle, it increases the physical...
electrocapillarity modulatorA type of optical modulator with potential application in optical switching and displays, in which applied voltage causes a...
photoemissive cell
photodetectorA photodetector, also known as a photosensor or photodiode, is a device that detects and converts light into an electrical...
goniophotometric curveThe graphed curve illustrating the directional reflectance of a sample for different angles of collection.
perovskiteThe term perovskite refers to a specific crystal structure commonly found in various materials. Perovskite structures have a...
endoscopeAn endoscope is a medical device used for visualizing and examining the interior of hollow organs, body cavities, or...
jig transitAn optical instrument containing a gimballed sighting telescope, used to measure angular relationships in horizontal and...
flow cytometryFlow cytometry is a powerful technique used in biology and medicine for the quantitative analysis of the physical and...
microcircuit manufacturingThe formation of transistors, diodes, capacitors, resistors and other electronic elements directly on a flake of silicon by...
phaseIn optics and photonics, "phase" refers to a property of electromagnetic waves, such as light, that describes the position...
flame emission spectroscopyA technique in photometry that uses an oxyhydrogen or oxyacetylene flame to optically excite a solution containing the...
near-field scanningA measurement technique used to determine the spatial distribution profile of an electrical or optical quantity of interest...
extrinsic photoconductivityPhotoconductivity due to the addition of impurities or external causes.
Paschen seriesAn array of lines in the infrared region of the emission spectrum of atomic hydrogen. Their wave numbers are expressed by...
field stopAn aperture located at an image plane of an optical system that determines the size and shape of the image.
optical filterAn optical filter is a device that selectively transmits or blocks specific wavelengths, or colors, of light. Optical...
macro lensA camera lens, used in macrophotography, that is designed and corrected to produce optimum definition of a nearby object...
single-photon emission computed tomographyA medical imaging method in which gamma camera heads rotate about the patient to detect radionuclides, enabling physicians...
hand viewerA device small enough to be held in a hand that uses a magnifying lens and a translucent back to permit the viewing of...
mid-infrared cameraA mid-infrared camera is a type of imaging device designed to capture images in the mid-infrared (mid-IR) spectral range,...
abridged spectrophotometerAn instrument that uses optical filtration in order to measure the transmittance for a discrete range or specific number of...
laser crystalA laser crystal, also known as an active medium or gain medium, is a solid-state material used in the construction of...
photocathodeAn electrode used to release photoelectric emission when irradiated, making it then the irradiated negative electrode of a...
pixelA pixel, short for "picture element," is the smallest controllable element of a digital image or display. It is a...
spectral flow cytometrySpectral flow cytometry is an advanced flow cytometry technique that expands the capabilities of traditional flow cytometry...
Hubner rhombA glass rhomb that is used in photometry to compare two illuminated surfaces. This is accomplished by the rhomb's angles,...
chemical actinometerA light-sensitive detector having a chemical compound that reacts when exposed to light. It is used in photochemistry and...
microphotofabricationThe formation of microimages for microreduction. The technique is used, for example, in the production of precision reticles...
Michelson-Morley experimentAn optical experiment carried out conclusively in 1887 that demonstrated that the ether, a hypothetical medium postulated by...
cold mirrorA mirror whose coating serves to reflect visible radiation while transmitting the infrared.
Dogmar/Aviar lensA general-purpose lens, also known as the Celor lens, used widely in photography and commercial processing; it has the form...
fiber optic gyroscopeA fiber optic gyroscope (FOG) is a type of gyroscope that uses the interference of light waves to detect changes in...
photochemistryThe study of chemical reactions stimulated by the properties of light.
mosaic detector arrayA group of photosensors arranged in a grid-like pattern covering the entire field of view, enabling them to record it all at...
flicker photometerA bench photometer that depends on the inability of the eye to distinguish color in brief flashes of light. Any difference...
electrophotographThe image formed in electrophotography.
CMOS image sensorA CMOS image sensor, short for complementary metal-oxide-semiconductor image sensor, is a type of semiconductor device used...
double-crucible methodA method of fabricating an optical waveguide by melting the core and clad glasses in two suitably joined concentric...
avalanche photodiodeA device that utilizes avalanche multiplication of photocurrent by means of hole-electrons created by absorbed photons. When...
diamond-turned opticDiamond turning refers to a precision machining process used to produce complex optical components, particularly lenses and...
photographic resolutionA measure of the ability of a photographic system to record fine detail. Usually stated in terms of cycles per millimeter on...
photoelectric tube
underwater photographyThe field of photography concerned with the recording of subjects beneath the water with a watertight, water-resistant...
rare earth dopantsRare earth dopants refer to elements from the lanthanide series, also known as rare earth elements, that are intentionally...
optical testing instrumentAn optical testing instrument is a device or system used to evaluate and measure the performance, quality, and...
telephoto magnification
hypersensitizingWith respect to photography, the process used to increase the effective speed of an emulsion between manufacture and...
vertical external cavity surface-emitting laserA laser that has a surface-emitting semiconductor gain element coupled to an external mirror designed to complete the laser...
darkroomA room that is light-tight, permitting total darkness or illumination with a safelight when working with photosensitive...
Schottky-barrier IRCCDA form of infrared CCD that utilizes internal photoemission as a photodetection mechanism.
elbow telescopeA refracting telescope that uses a prism to bend the line of sight 90°.
optical tooling targetSets of paired lines carefully designed to give the most accurate pointing possible for various lengths of sight.
monomerA molecule that has the ability to chemically combine with other molecules to form a polymer, hence being capable of being...
gain-switchingGain-switching is a technique used in lasers to generate short pulses of light by modulating the gain of the laser medium....
ultraviolet fiber opticsUltraviolet (UV) fiber optics refers to optical fibers that are designed and optimized for the transmission of ultraviolet...
photon correlation spectroscopySpectroscopy used to study the concentration, diffusion and Brownian motion of small particles suspended in a fluid by...
orthiconA television camera tube in which a low-velocity electron beam scans a photoactive mosaic that has been created by an...
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...
photosensitive recordingThe recording achieved when a surface, illuminated by a signal-controlled light beam, emits electrons or reacts in some...
rise timeMeasurement of the time elapsed during the current output change from 10 to 90 percent in a photoconductor.
microdensitometerThe fundamental tool of microdensitometry, the microdensitometer is an instrument used for the precise measurement of...
nonlinear optical materialsNonlinear optical materials are substances that exhibit optical properties that are not linearly proportional to the...
photonic crystalsPhotonic crystals are artificial structures or materials designed to manipulate and control the flow of light in a manner...
lock-in amplifierA lock-in amplifier is a specialized electronic instrument used to extract and measure small signals embedded in noise or...
optical glassOptical glass refers to a type of glass specifically engineered and manufactured for use in optical components and systems,...
laserA laser, which stands for "light amplification by stimulated emission of radiation," is a device that produces coherent and...
photoelectric colorimeterA system having a photoelectric detector for the measurement of three quantities related by linear combination to...
nanopositioningNanopositioning refers to the precise and controlled movement or manipulation of objects or components at the nanometer...
radioautographThe photographic image of a thin specimen having a radioactive isotope that, formed through contact between the specimen and...
time-to-amplitude converterA time-to-amplitude converter (TAC) is an electronic circuit that converts a time interval between two events into an...
Foucault knife-edge testThe Foucault test is performed by moving a knife edge laterally into the image of a small point source. The eye, or a...
photoemission
hematofluorometerA photoanalytical instrument for analysis of jaundice conditions in infants that measures bilirubin (a breakdown product of...
infrared photodetector arrayAn impurity-doped silicon detector array sensitive to long infrared wavelengths, installed in optical collecting systems...
photoluminescence mappingA technique used for noncontact inspection of semiconductor wafers. The material is illuminated by an excitation source that...
nonradiative transitionA nonradiative transition refers to a process in which an electron or an atom undergoes a change in its energy state without...
penta prismA five-sided prism containing two reflecting surfaces at 45° to each other, and two refracting faces perpendicular to...
lenticular color photographyA type of additive color photography using a lenticular structure impressed on a film base and a camera lens with a filter...
aerial mappingThe use of photographs taken from the air to construct graphic maps and charts of ground surfaces.
automatic optical inspectionA system for automatic industrial process control or measurement, consisting of an optical module for image acquisition, a...
quantum dotsA quantum dot is a nanoscale semiconductor structure, typically composed of materials like cadmium selenide or indium...
azimuthal polarizationAzimuthal polarization refers to a specific polarization state of light where the electric field vector of the...
nematic phaseA form of liquid crystal with an appearance of moving, threadlike structures, particularly visible when observed in thick...
angle of refractionThe angle formed between a refracted ray and the normal to the surface. This angle lies in a common plane with the angle of...
high contrastA term used to describe a photograph, film or television picture where the values for black and white areas are at or near...
tripletA lens assembly made up of three lens elements that may or may not be cemented.
electroluminescent-photoconductive image intensifierA panel of photoconductive and electroluminescent layers used as either a positive or negative image intensifier, depending...
surface-emitting laser diodeA semiconductor laser diode that emits light perpendicular to the active region. The output radiation is taken through the...
isophotometerA direct recording photometer that is designed to scan a photographic negative to determine its points of isodensity.
hill cloud lensA fish-eye lens designed to photograph cloud formations over the entire visible sky.
contrast filterA filter designed to improve contrast in an imaging system. For visual and black and white photosystems, a yellow filter is...
charge-coupled deviceA charge-coupled device (CCD) is a type of electronic image sensor used in various imaging devices, including digital...
photoelectric fluorometerA filter fluorometer that uses a photomultiplier tube to detect the fluorescence of a sample.
germanium detectorA type of photoconductive detector in which germanium, usually doped with boron, gallium and indium, serves as a...
responsive quantum efficiencyThe number of electrons emitted per photon incident upon a photodetector.
optoelectronicsOptoelectronics is a branch of electronics that focuses on the study and application of devices and systems that use light...
critical illuminationIllumination in which the light source is imaged at the object.
light meterAny device that is used to sense and measure light. See exposure meter; photoelectric exposure meter; photoelectric...
photofabricationThe use of photoetching techniques to produce small tools, parts and dies from sheet metal.
data busA system incorporated into fiber optic data communications characterized by several spatially distributed terminals that are...
x-ray analysisThe series of processes used to identify and evaluate crystal structure by using crystalline solids to diffract x-rays. In...
keystone distortionA type of geometrical distortion that brings about a trapezoidal display of a nominally rectangular picture. Usually...
traveling wave phototubeA traveling wave tube (TWT) containing a photocathode and window that, receiving a laser beam, produces a modified...
chemical vapor depositionChemical vapor deposition is a process of applying dopants to a glass bait by flame reactions of gaseous compounds. See also...
fused quartz and silicaFused quartz and silica are closely related materials, both composed primarily of silicon dioxide (SiO2), but they are...
light filamentPhenomenon caused by an ultrashort and ultra-intense light pulse propagating in a Kerr medium, such as air or water. When...
integrating sphereA hollow sphere coated internally with a white diffusing material and provided with openings for incident beam, specimen and...
Wollaston prismA polarizing prism consisting of two calcite prisms cemented such that they deviate the two emerging beams (which are...
fluorophoreA fluorophore is a molecule or a portion of a molecule that has the ability to emit light upon excitation by an external...
fiber optic preformA fiber optic preform is a cylindrical glass rod or tube used as the starting material for manufacturing optical fibers. It...
Fresnel rhombA type of quarter-wave retarder in the form of a glass rhomb; light entering the retarder undergoes two total internal...
electric-discharge lampA lamp that uses the transmission of an electric current through a gas or vapor to produce illumination. Neon, mercury and...
photographic sensitometer
astigmatismA lens aberration that results in the tangential and sagittal image planes being separated axially.
Fraunhofer hologramA far-field pattern holographically reproduced image that is categorically considered with three-dimensional lensless...
ultraviolet photomicrographyThe photographic recording that uses ultraviolet radiation to irradiate the microscope sample being examined and to form an...
distortionA general term referring to the situation in which an image is not a true-to-scale reproduction of an object. The term also...
design and engineering consulting servicesDesign and engineering consulting services refer to professional services provided by specialized firms or individuals to...
photoconductivityThe conductivity increase exhibited by some nonmetallic materials, resulting from the free carriers generated when photon...
photolysisThe photochemical reaction of light present in the decomposition of a substance.
visual photometerA photometer that permits visual comparison of the luminance of two surfaces.
chemical vapor deposition equipmentChemical vapor deposition (CVD) equipment refers to a class of specialized apparatus used in the process of chemical vapor...
photographic fieldThe maximum angle of view that can be recorded by a camera. Field is a function of lens focal length and film format.
rectificationA technique used in photogrammetry to ensure parallelism during projection printing. Failure to do this will change a...
lenticular stereogramThe stereo image that is recorded by the lenticular, stereo photographic process.
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...
Young's two-slit interferenceThe method by which Thomas Young in 1802 disproved Newton's corpuscular theory of light by the formation of interference...
photoelectric receiverAn instrument that uses a photocell to detect and measure the intensity of incident light.
spectroheliographAn instrument in which an image of the sun is scanned by the entrance slit of a monochromator, the exit slit simultaneously...
spectrogrammetric reading equipmentSpectra can be conveniently recorded on photographic film or plates. The portions that are occupied by regions of the...
Herschel effectThe decrease in effect in developable density on a photographic plate formed by a second exposure to radiation having a...
mesopic visionVision at intermediate levels of luminance between photopic and scotopic vision, where both retinal cones and retinal rods...
photodynamic inactivationPhotodynamic inactivation (PDI) is a therapeutic approach that utilizes the combination of light, a photosensitizer, and...
angle of incidenceThe angle formed between a ray of light striking a surface and the normal to that surface at the point of incidence.
negative carrierThe structure that holds the photographic negative in a proper position that is both flat and parallel to the lens plane, as...
laser outputThe laser output refers to the generated and emitted light produced by a laser system. This output is characterized by...
bleach (or bleacher)A chemical used in the developing of positive photographs that incites oxidation and thereby dissolves the negative silver...
photometric cubeA prism used in a photometer for the adjacent comparison of separate luminance.
near-field holographyA lithography method that allows the transfer of fine-pitch gratings from a phase mask into photoresist. The exposure takes...
photochemical detectorAn instrument used to detect and measure radiant energy by the formation of a chemical reaction.
rolling shutter artifactsRolling shutter artifacts are distortions or visual anomalies that can occur in images or videos captured by cameras with...
camera obscuraA forerunner of the modern camera, this instrument had a focusable lens that produced a sharp image on the enclosure...
laser photochemistryThe study concerned with the stimulation of chemical activity by laser light as a result of the absorption of photons by a...
oscilloscopeA system in which a supplied signal causes the deflection of the electron beam in a cathode-ray tube, thus forming a visible...
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...
Galilean telescopeA refracting telescope that yields an erect image by the use of a positive lens for its objective and a negative lens for...
Weissenberg methodThe Weissenberg method, named after the German physicist Karl Weissenberg, is a technique used in x-ray crystallography for...
photocoagulatorAn optical medical instrument that uses an intense, precisely focused beam of light to stop weakened blood vessels from...
teleradiographyA method of taking radiographs at a distance from the object being photographed to decrease distortion.
grating beamsplitterA grating beamsplitter is an optical device that utilizes the principles of diffraction to split a beam of light into...
wedge photometerA photometer that uses a wedge, marked to show its reduction of flux density, to make two light sources equal in intensity...
x-ray detectorOne of various types of fluorescent screens used to detect x-ray radiation. Photographic film is mildly sensitive to x-rays,...
equidensitometry1. The use of an electronic microdensitometer to measure points of equal density on a photographic deposit. 2. A technique...
flash sensitometerA sensitometer that utilizes an electronic flashtube or a photoflash lamp as both the light source and the shutter for...
bimorphA type of piezoelectric translator that uses two thin strips of piezoelectric material, one expanding while the other...
Compton scatteringThe phenomenon observed by A.H. Compton in 1923 -- that some scattered radiation possesses a longer wavelength and...
hyperfocal distanceThat object distance at which a camera must be focused so that the far depth of field just extends to infinity. The near...
apochromatAn apochromat, often referred to as an apochromatic lens or apochromatic objective, is a type of optical system designed to...
photographic thermometryThe photographic recording of the heat radiation emitted from various points on the object as corresponding density...
spherical microintegrated lensA tiny lens (as small as 100 µm in diameter) used to focus light on charge-coupled devices, formed by heating a...
Baker-Nunn cameraA wide-field camera based on the classic Schmidt optical system used to photograph Earth-orbiting satellites.
modulation transfer functionAlso called sine wave response and contrast transfer function. The modulation transfer function is the ratio of the...
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...
fluorographyThe photographic recording of a visible image formed by the impact of invisible radiation on a fluorescent screen.
lens testing equipmentLens testing equipment refers to a range of specialized tools and instruments used to evaluate the optical performance,...
microchannel spatial light modulatorA device to modulate spatially a collimated coherent beam of light with input data in optical data processing. It uses a...
qubitA qubit, short for quantum bit, is the fundamental unit of information in quantum computing and quantum information...
mirror lensAn image-forming system having curved mirrors in place of transparent glass components. Mirror lenses are commonly used for...
photochromismThe reversible change in the absorption spectrum of certain compounds upon irradiation with a given wavelength of light.
multichannel direct-reading spectrometerAn instrument that contains a spectrograph with a grating in which an array of slits, in place of a photographic plate, is...
subtractive color processThe basic process of color photography whereby colors are subtracted from white light by means of filters, making all colors...
base-altitude ratioIn aerial photography, the ratio derived from a stereoscopic pair of photographs that represents the air-base length divided...
microchannel plateA microchannel plate (MCP) is a specialized electron multiplier device used in various applications such as particle...
inverse photoelectric effectThe changing of the kinetic energy of a mobile electron into radiant energy, as in formation of x-rays.
absorption spectrophotometerMeasures the absorption or sample transmittance over a range of specified wavelengths. Sample may be placed within the...
infrared photomicrographyPhotographic recording that uses infrared radiation as the light source to form an image of a microscopic object and a...
equidensities1. A contour map of a photographic deposit consisting of lines and curves that join points of equal density. 2. The...
image qualityA measure of the closeness with which an optical image is capable of resembling the original object. The factors that affect...
photoelectric reflectometerA photoelectric photometer used to measure the reflectance of a surface.
solitonAny isolated wave that propagates without dispersion of energy. Specifically to photonics, an ultrashort pulse of laser...
excitonAn exciton is a quasiparticle that represents the bound state of an electron and a hole in a solid-state material, typically...
photoswitchA solid-state device that acts as a high-speed power switch, and that is activated by incident radiation.
optical fiberOptical fiber is a thin, flexible, transparent strand or filament made of glass or plastic used for transmitting light...
reflectiveThe term reflective is an adjective that describes the ability of a surface or material to reflect light or other forms of...
stereoscopeA small instrument containing a picture support and a pair of magnifying lenses so arranged that the left eye sees only the...
photoelectric multiplierA phototube in which the primary photoemission current, before being extracted at the anode, is multiplied many times.
photochromatic compoundA chemical compound that exhibits a reversible change in its absorption spectrum upon irradiation with given wavelengths of...
spectrophotoelectricCharacteristic of the relationship between photoelectric activity and the wavelength of incident radiation.
photonic cavityA photonic cavity, also known as an optical cavity, is a structure that confines electromagnetic radiation within a certain...
definition test objectA chart, either printed on paper or prepared photographically on glass plates or film, that consists of 3-bar resolution...
aspheric lensAn aspheric lens is a type of lens whose surface profiles deviate from the traditional spherical shape. Unlike spherical...
image iconoscopeA camera tube similar in design to the iconoscope. However, the image formed in the image iconoscope is projected on a...
photometricPertaining to the measurement of the intensity of light.
detector1. A device designed to convert the energy of incident radiation into another form for the determination of the presence of...
photostoreThe photographic recording of data, in binary form, for storage in memory. Exposure is achieved by a cathode-ray tube or by...
photon counterA device used to evaluate the luminance of a surface by determining the number of photons emitted from a sample surface area.
optical distanceThe physical length of the light path in a substance divided by the refractive index of that substance. See also equivalent...
embedded laserThe term "embedded laser" typically refers to a laser device that is integrated or embedded into a larger system or...
uniformly redundant arrayArray used in coded-aperture imaging experiments with two-beam CO2 lasers that provide an artifact-free process, faithful...
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...
ultramicrophotographyThe process of microphotography that involves the reduction of the original at a ratio greater than 100 to 1. The process is...
Marx effectThe decrease in the energy of a photoelectric emission as a result of the simultaneous incidence of radiation having lower...
developerA chemical solution that changes the silver salts (latent image) of exposed photographic film into black metallic silver...
photon burst detection of fluorescenceA type of laser spectroscopy used to measure short-lived isotopes by observing sudden bursts of fluorescence resulting from...
stereocomparator1. A stereoscope that has adjustable scales to allow the determination of distances and dimensions from stereoscopic...
photodiodeA two-electrode, radiation-sensitive junction formed in a semiconductor material in which the reverse current varies with...
rhomboid prismA reflecting prism that is rhomboidal in shape. It has two parallel transmitting faces, and two parallel reflecting faces;...
dynodeThe auxiliary electrode in a photomultiplier that gives rise to secondary emission and amplification when bombarded by...
fractional photothermolysisA laser skin-resurfacing method that creates microscopic thermal wounds referred to as microscopic treatment zones (MTZs),...
refractive index contrastA measure of the relative difference in refractive index between two optical materials. Most commonly used in fiber optics...
emission spectrumAn emission spectrum is a graphical representation or a characteristic pattern of the wavelengths or frequencies of light...
Brillouin scatteringBrillouin scattering is a phenomenon in physics where an incident electromagnetic wave (usually light) interacts with...
phototheranosticsPhototheranostics, a portmanteau of "photo" (light), "therapy," and "diagnostics," refers to an emerging field that combines...
cathode-ray tube faceplateA fiber optic end plate constructed by drawing a bundle of parallel fibers embedded in glass and cutting it into thin...
photon sieveA photon sieve is an optical device used in the field of optics and imaging. It's designed to focus and shape light,...
calcium indicatorA calcium indicator is a molecule that is sensitive to changes in calcium ion (Ca2+) concentrations in biological systems....
masks for evaporation/depositionIn the context of thin film deposition processes such as evaporation or sputtering, masks are used to selectively deposit...
atomic scattering factorThe efficiency of scattering by an atom in a particular direction, expressed as: where AA is the amplitude of the wave from...
Planck's (radiation) lawThe formula describing the spectral radiant emittance of a perfect blackbody as a function of its temperature and the...
Dobson spectrophotometerA spectrophotometer that measures the amount of ozone in the atmosphere through a comparison of solar energy at two...
Littrow prismA 30-60-90° spectrograph prism that is coated on the surface opposite the 60° angle with a reflecting film.
imagery rectificationPhotogrammetric compensation for incidental camera movement (which prevents attainment of true vertical photographs) whereby...
collimatorAn optical instrument consisting of a well- corrected objective lens or mirror with a light source and or object/image (i.e....
phototransistor tachometerA tachometer consisting of a light source, rotating perforated wheel and phototransistor to measure the rates of rotation 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...
ophthalmoscopyAlso referred to as fundus photography, ophthalmoscopy is the dioptrical study of the various interior components of the eye...
electron-gun systemAn electron-gun system is an assembly used to generate and control a focused beam of electrons. Electron guns find...
dark noiseThe noise produced in a photodetector when the photocathode is shielded from all external optical radiation and operating...
telephoto lensA compound lens so constructed that its overall length is equal to or less than its effective focal length.
optical noiseOptical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or...
sensitometryPrimarily the measurement of photographic sensitivity of certain materials such as photographic film. It refers to the...
aspheric mirrorAn aspheric mirror is an optical mirror surface that deviates from the shape of a perfect sphere, having a non-spherical...
photocell
Sonnar lensA photographic objective that uses the thick meniscus principle to obtain its power. It is designed to photograph small...
mask spectrometerInstrument that uses absorption spectroscopy to detect gases in planetary atmospheres. Dispersed incoming radiation is...
immersion liquidTerm synonymous with refractive index liquid, but related more to tank or chamber immersion of crystals, fibers, lenses,...
internal photoelectric effectThe creation of free electrons within a solid by the absorption of a sufficient amount of photons. The effect produces an...
Nd:YAG laserNd:YAG laser refers to a solid-state laser that utilizes neodymium-doped yttrium aluminum garnet (Nd:Y3Al5O12) as the gain...
deep ultravioletDeep ultraviolet (DUV or deep-UV) refers to a specific range of ultraviolet light with shorter wavelengths than those in the...
photoresistPhotoresist is a light-sensitive material used in photolithography processes, particularly in the fabrication of...
character read-out systemA photoelectrically controlled, alphanumeric reading device that converts characters to audible or sorting signals which can...
chief rayThe ray that passes through the center of the aperture stop in an optical system. It often is called the principal ray of an...
infrared lensAn infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating...
minimum object distanceMinimum object distance, often abbreviated as MOD, refers to the closest distance at which a camera lens or optical system...
Fraunhofer linesThe dark absorption lines observed in the spectrum of the photosphere of the sun. There are thousands of these lines, the...
Abbe prismA form of roof prism used to invert an image. The prism has faces cut normal to the optical axis; therefore, the prism may...
bubble chamber photographyThe photographic recording of gas bubbles produced when particles traverse liquid hydrogen in a bubble chamber.
light-beating spectroscopyThe spectroscopic analysis of optical line shapes and frequency shifts, using the technique of light beating; i.e., the...
photoelectric photometryThe use of photoelectric sensors to detect and measure the intensity of a light source. This application, as compared to...
Haidinger fringesAlso known as constant angle or constant deviation fringes. The interference fringes observed with dense flat plates near...
electronic shutterA mechanical shutter that has had its timing escapement replaced with an electronic timing circuit. This circuit allows a...
photoacoustic spectroscopyA method for obtaining the optical absorption spectra of solids, semisolids, liquids and gases. PAS is inherently...
Fourier transform spectrometerAn instrument using a Michelson interferometer, a beamsplitter, two plane mirrors and a detector to give Fourier analysis of...
platinum silicideA semiconductor material used in photodetectors, sensitive in the infrared up to 5 µm.
optical camouflageThe use of retroreflective projection technology (RPT) to project a background image onto a masked object, such as a vehicle...
aplanatic pointsAplanatic points refer to specific points in an optical system where certain aberrations, such as spherical aberration or...
microphotographA photograph reduced to the microscopic scale and stored on a microfilm as seen with microfiches for the purpose of storing...
clear eye distanceIn a visual optical system, the axial distance from the last mechanical surface of the eyepiece to the exit pupil.
attenuatorAn electronic transducer, either fixed or adjustable, that reduces the amplitude of a wave without causing significant...
swept-source laserA swept-source laser, also known as a wavelength-swept laser, is a type of laser that rapidly and continuously changes its...
random access multiphoton microscopyAlso known as RAMP microscopy, random access multiphoton microscopy is a microscopic technique that uses multiple...
InGaAs photodiodeAn InGaAs photodiode refers to a photodetector device that is constructed using a semiconductor material composed of a...
image amplifierAn electro-optic system using, in general form, an evacuated glass envelope with a semitransparent photocathode at one end...
phase hologramA hologram that is formed on a recording medium by changing the phase of the illuminating wave in correspondence with the...
hologramAn interference pattern that is recorded on a high-resolution plate, the two interfering beams formed by a coherent beam...
biostimulationThe action of a biological system responding to a single or multiple coherent particles of light produced from a laser...
densitometer1. An instrument used to measure the opacity or density of dyes, pigments or dispersed particles that form an image in or on...
self-electro-optic effect deviceAn optically bistable device used for photonic switching, constructed of a multiple quantum well biased by an external...
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