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optical Dictionary Terms

communicator bandwidth
The maximum rate at which temporally disjunct optical signals can be produced or detected.
acrylic
A thermoplastic or optically transmitting hard plastic produced by applying polymerization initiator and heat to a monomer.
zero-dispersion wavelength
In a single-mode optical fiber, the wavelength that causes material dispersion and waveguide dispersion to cancel each...
coherent communications
A fiber optic communications system that works on the principles of homodyning or heterodyning. The transmitting laser...
modulation frequency
Rate at which optical radiation or a signal is varied through the use of a mechanical or electronic chopper. Also called...
acceptance pattern
A curve expressing an optical fiber's total transmitted power as a function of its launch angle at the input.
diamond turning
Diamond turning, also known as diamond machining or diamond cutting, is a precision machining process used to produce...
optical wireless
 planform bonding
A manufacturing process used to construct substrates for large optical components. Used with IR materials, planform bonding...
indent
A flaw deliberately introduced into an optical fiber to prepare it for cleaving.
Franz-Keldysh effect
Observed lengthening in wavelengths of the optical absorption edge of a semiconductor with the application of an electric...
GaAlAs laser
A GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic...
time-domain reflectometer
See optical time-domain reflectometry (OTDR).
zoom
To control, by magnifying or reducing, the size of a televised image, either electronically or optically.
meridional plane
That plane in an optical system containing its optical axis and the chief ray. Also called the tangential plane.
rare earth dopants
Rare earth dopants refer to elements from the lanthanide series, also known as rare earth elements, that are intentionally...
anisotropy
Anisotropy refers to the property of exhibiting different values or characteristics when measured in different directions....
laser photocoagulator
Optical source intended to reduce bleeding as well as to abet wound or vessel healing through cauterization, used in eye...
lateral offset loss
A power loss caused by transverse or lateral deviation from optimum alignment of source to optical waveguide, waveguide to...
optical design software
Optical design software refers to specialized computer programs used by optical engineers, physicists, and designers to...
light field
The term light field refers to the spatial distribution of light rays traveling in all directions through a given space. It...
spectrograph
An optical instrument for forming the spectrum of a light source and recording it on a film. The dispersing medium may be a...
phase-modulated sensor
A phase-modulated sensor is a type of sensor that uses modulation of the phase of a signal to measure changes in a physical...
laser trapping
A technique for confining atoms, molecules or small particles within one or more laser beams. This can be accomplished...
definition
The clarity of an optically reproduced image. Definition is produced by the combination of resolution and acutance.
line of sight
The line of vision; the optical axis of a telescope or other observation system. The straight line connecting the object and...
microlens array
A microlens array is a grid-like structure composed of numerous small lenses, typically arranged in a regular pattern. Each...
MEMS fiber optic switch
A MEMS fiber optic switch is a microelectromechanical system (MEMS) device designed to selectively route optical signals...
nanophotonics
Nanophotonics is a branch of science and technology that explores the behavior of light on the nanometer scale, typically at...
optoelectronic shutter
A device used to control or block a light beam by means of the Kerr electro-optical effect, and other electro-optic devices...
material scattering
The total scattering attributable to the intrinsic properties of the materials through which an optical wave is propagating.
diffuse reflectance spectroscopy
Diffuse reflectance spectroscopy (DRS) is a nondestructive analytical technique used to investigate the optical properties...
mode-locked lasers
Mode-locking is a technique used in lasers to produce ultrashort pulses of light with durations on the order of picoseconds,...
V-groove
A V-shaped channel pressed or etched into a substrate, in which, for example, optical fibers may be placed to create an...
Fresnel reflection method
A method for measuring the index profile of an optical fiber by measuring the reflectance as a function of position on the...
interferogram
A photographic or electronic recording of an optical interference pattern.
patina
A thin film or coating that forms on various finished surfaces. On optical surfaces it usually denotes aging.
parabolic profile
The condition in which the index of refraction in an optical fiber varies as a parabolic function of the radius.
infrared optic
Infrared optics refer to optical components and systems designed to manipulate and control infrared (IR) light, which lies...
proof strength
The minimum amount of strength characteristic of an optical fiber, as determined by proof stressing; expressed in thousands...
pit
The micrometer-size depressions that store data digitally in an optical data storage medium.
pharyngoscope
An optical system used to examine the pharynx.
corrector plate
An optical element designed to correct each zone of a reflector or refractor for spherical aberration.
frequency doubling
A nonlinear optical process in which the frequency of an optical beam is doubled coherently.
near-field scanning optical microscope
A scanning probe microscope that analyzes the surface of a specimen by recording the intensity of light as it is focused...
radial gradient
In gradient index optics, a gradient profile in which the index varies in a direction perpendicular to the optical axis....
beat length
A characteristic of optical fiber used to calculate the fiber's ability to maintain polarization. The beat length describes...
tellurium
The material favored for study of interaction of high-acoustic intensities with free carriers. Tellurium is the...
tracking
1. The process of following an object's movement; accomplished by focusing a radar beam on the reticle of an optical system...
sapphire crystal
Sapphire crystal refers to a transparent, single-crystal form of aluminum oxide (Al2O3) known as corundum. It is one of the...
meta-optics
Meta-optics, also known as metasurface optics or flat optics, is a branch of optics that involves the design, fabrication,...
focal point
That point on the optical axis of a lens, to which an incident bundle of parallel light rays will converge.
principal point
The intersection of the principal plane and the optical axis of a lens.
biocular
A term pertaining to devices (generally optical) designed for use with both eyes viewing through a single exit pupil. The...
optical time-domain reflectometry
A method for characterizing a fiber wherein an optical pulse is transmitted through the fiber, and the resulting light...
surface-enhanced Raman optical data storage
A technique of optical storage whereby information is encoded by molecular alterations in the interaction between the...
coded disc
A reticle carrying patterns of various forms that can be rotated in an optical beam to cause variations in the intensity of...
decentering
1. The grinding or edging of a lens so that the geometrical center and optical center do not coincide. 2. The shifting of an...
aspheric mirror
An aspheric mirror is an optical mirror surface that deviates from the shape of a perfect sphere, having a non-spherical...
concave and convex spherical mirror
Concave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These...
path-reversal principle
The criterion maintaining that if light follows a specific path through an optical system, it will, if reversed, traverse...
infrared optical material
The range of materials that, unlike glass, may be used in the infrared. Water-soluble salts, such as cesium iodide, and...
image jump
In optics, the term image jump refers to a displacement or shift in the apparent position of an image when a change occurs...
nonlinear optical detector
A type of radiation detector designed to recognize nonlinear optical effects, such as the Raman effect, by means of a...
aspheric lens
An aspheric lens is a type of lens whose surface profiles deviate from the traditional spherical shape. Unlike spherical...
core-coupled lens
A semispherical or conical lens created directly on the core of an optical fiber to focus light from a laser into the fiber...
quantum cascade laser
A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics....
photodarkening
The effect that the optical losses in a medium can grow when the medium is irradiated with light at certain wavelengths.
zero order
In an interference pattern, that point where there is no difference between the optical paths of the interfacing wavefronts.
catoptric system
An optical system in which the only image-forming elements are curved-surface mirrors; e.g., a Cassegrain lens system.
polycrystal
A substance that transmits the infrared, but which is too delicate or fragile to be used in the form of a single crystal....
fiber optic imaging bundle
A fiber optic imaging bundle is a specialized optical device composed of multiple optical fibers bundled together. Each...
optical microphone
Laser-powered telephone device for analog communications that employs a vibrating plastic membrane as a transmitter to...
point spread function
The point spread function (PSF) is a fundamental concept in imaging that describes the response of an imaging system to a...
beamwidth
The angular width of a radiation beam. With respect to a conical beam of light, it is the vertex angle of the cone. The...
injection molding
A method of producing high-quality plastic optics in large volumes by injecting the heated, liquified plastic at high...
dots per inch
A measurement of the spatial resolution of a line or area array in an optical character recognition scanning device.
light filter
A homogeneous optical medium or coating that transmits only in particular regions of the spectrum. It is used to change or...
Q
The figure of merit of a resonator, defined as (2p) x (average energy stored in the resonator)/(energy dissipated per...
delta error
The term delta error (delta-E) generally refers to the difference or change in error between two values or states. The word...
focus control
1. A mechanism that permits the focusing of an optical system.2. A means of obtaining the sharpest image from a cathode-ray...
fiber optic preform
A fiber optic preform is a cylindrical glass rod or tube used as the starting material for manufacturing optical fibers. It...
optical channel monitor
An optical channel monitor (OCM) is a device used in optical communication systems to monitor and analyze the performance of...
self-absorption
In optical emission spectroscopy, the reduction in radiant power in the central portion of spectral lines arising from the...
centration
In a perfectly centered lens, the mechanical axis (defined by the ground outside the diameter of the lens) is made to be...
holographic grating
A holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists...
decentration aberration
An aberration occurring in a lens system when one or more of the centers of curvature of the optical surfaces do not...
magneto-optics
Magneto-optics refers to the study and manipulation of the interaction between magnetic fields and light (electromagnetic...
image inverter
A system of elements which rotates the optical image with respect to the optical axis by a factor of pi radians.
object distance
The distance between the object and the cornea, or the first surface of the objective in an optical device.
plasmonics
Plasmonics is a field of science and technology that focuses on the interaction between electromagnetic radiation and free...
limiting angle of resolution
The angle subtended by two points or lines that are just far enough apart to be distinguished as separate. The ability of an...
lens
A lens is a transparent optical device that focuses or diverges light, allowing it to pass through and form an image. Lenses...
sapphire
Sapphire refers to a crystalline form of aluminum oxide (Al2O3) that is used in various optical and photonic applications...
minimum angle of deviation
The smallest angle through which light is bent by an optical element or system. In a prism, the angle of deviation is a...
magnifying power
The ability of an optical system to make an object appear larger. An optical element or optical system causing an object to...
substage condenser
In a microscope, the optical assembly that focuses light on the specimen and into the objective.
embedded laser
The term "embedded laser" typically refers to a laser device that is integrated or embedded into a larger system or...
bench photometer
A device used to compare the luminous intensities of two sources by locating a point between the two light sources where the...
photon sieve
A photon sieve is an optical device used in the field of optics and imaging. It's designed to focus and shape light,...
grating beamsplitter
A grating beamsplitter is an optical device that utilizes the principles of diffraction to split a beam of light into...
afocal
An optical system with object and image points at infinity. Literally, "without a focal length."
button blocking
The production of a block by attaching the optical elements to a plate by means of individual buttons of pitch or other...
narrowband pyrometer
An optical pyrometer that is equipped with a narrow bandpass filter to transmit a limited number of wavelengths to the...
concentricity error
The distance between the center of the two concentric circles of an optical fiber that designate the diameter of the...
time-lapse optical coherence tomography
Time-lapse optical coherence tomography (OCT) refers to a medical imaging technique that captures a series of sequential OCT...
infrared reflector
An optical component coated to reflect infrared radiation. Gold, silver and aluminum are typical coating materials.
micrograph
A graphic reproduction of an object formed by a microscope or another optical system. Also an instrument used to make tiny...
holographic optical element
A component used to modify light rays by diffraction; the HOE is produced by recording the interference pattern of two laser...
topological photonics
Topological photonics is a branch of physics and optics that explores the application of topological concepts to the...
diffraction efficiency
Diffraction efficiency is a measure of how effectively a diffractive optical element (DOE) or diffraction grating directs...
multimode optical waveguide
An optical waveguide that will allow more than one bound mode to propagate.
incoherent bundle
A bundle of filaments of optical glass or other transparent materials that transmit only light, not optical images. The...
lab-on-a-chip
A lab-on-a-chip (LOC) is a miniaturized device that integrates various laboratory functions and capabilities onto a single,...
electroholography
A technology that uses electrically activated holograms stored within specially developed crystals to route information in...
anomaloscope
An optical instrument that uses a yellow light of varying intensity with red and blue lights of fixed intensity to test for...
Airy disc
The central peak (including everything interior to the first zero or dark ring) of the focal diffraction pattern of a...
optical profiler
Also known as a white-light interferometer. Measures surface texture and shape from nanometer-scale roughness to...
nanoparticle photonic resonator absorption microscopy
Nanoparticle photonic resonator absorption microscopy is a microscopy technique that combines the principles of photonic...
confocal resonator
A confocal resonator, also known as a confocal cavity or confocal laser resonator, is a type of optical resonator...
bend loss
The loss of optical power in an optical fiber because radiation escapes through its bends. The radiation loss caused by...
optical testing instrument
An optical testing instrument is a device or system used to evaluate and measure the performance, quality, and...
low
Term used to describe an optical surface that contacts the test glass only at its edges.
telescope
An afocal optical device made up of lenses or mirrors, usually with a magnification greater than unity, that renders distant...
wedge filter
An optical filter so constructed that the density increases progressively from one end to the other, or angularly around a...
infrared camera
An infrared camera, also known as a thermal imaging camera or IR camera, is a device that captures and visualizes the...
phase contrast microscopy
Phase contrast microscopy is an optical microscopy technique that enhances the contrast of transparent and colorless...
microphotometer
An instrument capable of measuring the transmitted or reflected luminance from a very small area seen under a microscope....
leman prism
An erecting prism that inverts and reverses the image. It displaces the optical axis but does not deviate it.
optical axis
The imaginary line passing through both the centers of curvatures of the optical surfaces of a lens or mirror; the optical...
optical emission spectroscopy
In dry etching, a method of characterizing the composition of solid materials such as metal. Atoms in the OES technique are...
single-photon avalanche diode
A single-photon avalanche diode (SPAD) is a specialized type of photodetector designed to detect extremely weak optical...
optical analysis
The mathematical evaluation of an optical system to determine and quantify its basic optical properties and image quality...
focometer
A device used to measure the focal length of an optical system or lens.
laser pointer
Handheld optical laser device containing a semiconductor or DPSS source. The output is corrected via internal collimating...
optical link
Any optical transmission channel used in telecommunications designed to connect two end terminals or to be connected in...
launch angle
The angle between the light input propagation vector and the optical axis of an optical fiber or fiber bundle.
scaling law
In coherence theory, an optical law put forth by physicist Emil Wolf that explains the behavior of light as it travels away...
boundary extraction
In optical character recognition, an intermediate step between character location and feature extraction.
solid-state laser
A solid-state laser is a type of laser that uses a solid gain medium (as opposed to a liquid or gas) to produce coherent...
residual absorption and scattering
Loss mechanisms that degrade the performance of all thin-film optical devices by removing radiant flux out of the specular...
blocking material
Pitch, wax, resin or other cement suitable for holding optical parts to a spindle during grinding and polishing processes.
nanopositioning
Nanopositioning refers to the precise and controlled movement or manipulation of objects or components at the nanometer...
optical figure
The amount by which an optical surface deviates from its ideal design value, expressed in wavelengths of light. Optical...
intermediate frequency
In a heterodyne optical receiver, the frequency that is the difference between that of an incoming laser signal and that of...
laser annealing
Laser annealing is a process that involves using a laser beam to heat and modify the microstructure of a material, typically...
microbending loss
Transmission loss in optical fibers caused by packaging processes; it is considered a power-coupling effect from the guided...
Geometrical optics
The area of optics in which the propagation of light is described by geometrical lines (or rays) governed by Fermat's...
mercury arc
An electric arc that is formed in mercury vapor through which an electric current flows. The intensity of the illumination...
optical fiber
Optical fiber is a thin, flexible, transparent strand or filament made of glass or plastic used for transmitting light...
monomode optical waveguide
blaze height
Blaze height typically refers to a parameter in the context of diffraction gratings, which are optical devices consisting of...
Martens wedge
A wedge-shaped piece of quartz typically found in a polarimeter to monitor and rotate the plane of polarization of plane...
characteristic angle
The angle at which a given mode propagates down an optical fiber.
dichroic mirror
A dichroic mirror, also known as a dichroic beamsplitter or interference filter beamsplitter, is an optical device that...
Nd:YAG laser
Nd:YAG laser refers to a solid-state laser that utilizes neodymium-doped yttrium aluminum garnet (Nd:Y3Al5O12) as the gain...
laser tweezers
A technique based on the principles of laser trapping and used to manipulate the position of small particles by gradually...
cladding ray
A ray that is reflected into the core of an optical fiber from the outer surface of the cladding.
Faraday configuration
Describes incident radiation propagating parallel to an externally applied magnetic field in magneto-optical experimentation.
photoacoustic spectroscopy
A method for obtaining the optical absorption spectra of solids, semisolids, liquids and gases. PAS is inherently...
retroreflector
A retroreflector is an optical device or structure that reflects incident light or electromagnetic waves back to their...
overfill
The condition of the numerical aperture or beam diameter of the laser, LED, or other optical source being larger than the...
microdensitometer
The fundamental tool of microdensitometry, the microdensitometer is an instrument used for the precise measurement of...
nonlinear optical crystal
An optical crystal that possesses a strong nonlinear dielectric response function to optical radiation. A material with a...
cord
A threadlike inclusion within a blank of optical glass. Rarely found in quality optical materials.
HE11 mode
Designation for the fundamental mode of an optical fiber.
aplanatic surface
An aplanatic surface is an optical surface that is specifically designed or shaped to minimize spherical aberration and...
deflection under static load
For an optical table, the amount of displacement that occurs when a heavy load is placed or moved on the surface. To measure...
vertical external cavity surface-emitting laser
A laser that has a surface-emitting semiconductor gain element coupled to an external mirror designed to complete the laser...
optical diode
See Faraday rotation; optoisolator.
Bragg grating
A filter that separates light into many colors via Bragg's law. Generally refers to a fiber Bragg grating used in optical...
bronchoscope
An optical instrument designed to permit the visual examination of the interior of the bronchi.
ellipsometry
Ellipsometry is an optical technique used to characterize the properties of thin films and surfaces. It is based on the...
soleil compensator
An optical compensator similar to the Babinet compensator, but which produces a phase-change consistent throughout its...
body
In the optical field, a piece of glass to which a lens or prism is cemented. The unit is ground and polished as a whole to...
microbending
In optical fiber, sharp but microscopic curvatures that create local axial displacements of a few microns and spatial...
cylindrical lens
A cylindrical lens is an optical component that has different curvatures along its two orthogonal axes, resulting in a shape...
barium fluoride
A relatively hard crystal, highly resistant to excessive energy radiation, that is frequently used for optical windows,...
optical coatings
Optical coatings are thin layers of materials applied to optical components, such as lenses, mirrors, filters, and prisms,...
energy-sharing laser
A laser that distributes its output power among two, three or four optical fibers simultaneously.
polariton
A polariton is a quasiparticle resulting from the strong coupling between photons (light particles) and certain types of...
modal noise
In an optical system, noise created by mode-dependent optical losses and variations in the distribution of radiant power...
chalcogenide
Chalcogenide refers to a class of compounds containing elements from group 16 of the periodic table, which includes sulfur...
decision-theoretic character recognition
An approach to optical character recognition based on matching the input character against a set of stored prototypes.
flying spot scanner
A device used to scan, with a small, intensely bright spot, portions of a picture surface and to transform the original...
PLZT
A transparent lead-lanthanum zirconate titanate ceramic with optical qualities that can be controlled by applying voltages...
freeform optics
Freeform optics refers to the design and fabrication of optical surfaces that do not follow traditional symmetric shapes,...
gimbal mount
An optical mounting device that permits adjustment around two perpendicular and intersecting axes of rotation.
nonlinear scattering
Direct conversion of a photon from one wavelength to a lower energy photon of another wavelength(s) due to inelastic...
interferometric calorimetry
Heat measurement method in which the sample is made part of the interferometer and the temperature increase is determined by...
angle of convergence
An angle formed by the lines of sight of both eyes when focusing on an object. Also, the rate at which a ray approaches the...
stress corrosion
A type of fatigue found in optical fibers, caused by water or another corroding agent.
custom lapping and polishing services
Custom lapping and polishing services involve specialized processes used to improve the surface finish and dimensional...
micro-ring resonator
A micro-ring resonator is a compact optical device that utilizes the resonant behavior of light within a small ring-shaped...
optical bench
A support for optical parts comprising a solid bed that permits precise longitudinal movement of one component relative to...
optical system
A group of lenses, or any combination of lenses, mirrors and prisms, so constructed as to refract or reflect light to...
flame emission spectroscopy
A technique in photometry that uses an oxyhydrogen or oxyacetylene flame to optically excite a solution containing the...
incoherent holography
The production of holograms initially from either conventional photographs or incoherent optical equipment.
void
A blank area (caused by insufficient inking of the paper) that falls within the range of an intended character stroke in an...
photonics
The technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon. The...
receiver
A detector and signal demodulator used in optical communications systems to receive a signal and often to translate it into...
laser spark spectroscopy
A method of analysis in which a pulsed laser beam is used to heat a particle, producing a plasma, or laser spark. As the...
ultrafast pulsed laser
An ultrafast pulsed laser is a type of laser that emits extremely short pulses of light with durations typically on the...
beam matrix
1. A geometrical arrangement of two or more light beams for use in laser shows, object detection or other applications...
spectrum
See optical spectrum; visible spectrum.
laser oscillator
Contains the light or beam path within a laser device. The oscillator uses reflective optical components that are oriented...
optical pyrometer
An instrument for determining the temperature of a hot object by examining the color spectrum of the visible light it gives...
strain
In optics, the mechanical tension, compression or shear in optical glass due to internal stress caused by improper cooling...
Abbe constant
A dispersion relation defined in order to value the reciprocal amount of dispersion. It is defined as the refractivity over...
infrared window
1. A thin parallel plate of material that transmits in the infrared region. See infrared optical material. 2. A spectral...
Seidel aberrations
Seidel aberrations refer to a set of monochromatic aberrations in optical systems, named after the German mathematician and...
transversely excited atmosphere carbon dioxide laser
Abbreviated TEA CO2 laser. A gas laser that provides shorter pulses and higher peak powers than conventional CO2 lasers. The...
refractive index contrast
A measure of the relative difference in refractive index between two optical materials. Most commonly used in fiber optics...
optical camouflage
The use of retroreflective projection technology (RPT) to project a background image onto a masked object, such as a vehicle...
optical disc
A rigid medium, generally a polycarbonate substrate coated with a reflective aluminum layer, that stores information (such...
lattice
In photonics, a lattice refers to a periodic arrangement of optical elements or structures, often on a microscopic or...
CCD image sensor
A CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images...
microdisplay
A microdisplay is a miniature electronic display technology that is designed to project visual information onto a small...
Abney effect
The alteration and reduction of color with the addition of white light. The perceived color shift that occurs as the...
correction wedge
In rangefinders and height finders, a rotatable or sliding wedge-shaped element used to divert the line of sight precisely...
mode volume
The number of bound modes that an optical waveguide is capable of supporting.
converging surface
The curved boundary between two optical media of different refractive indices, which causes convergence.
germanate glass
A type of glass used in near-infrared optical components, in which germanium is used as a cation instead of silicon.
infrared photodetector array
An impurity-doped silicon detector array sensitive to long infrared wavelengths, installed in optical collecting systems...
fiber photometry
An optical recording technique that uses light source(s), a beamsplitting cube, light detector(s) and an optical fiber...
peripheral
Near the boundary or edge of the field of an optical system; the outer fringe.
inside vapor-phase oxidation
A method that produces low-loss optical fibers. A glass tube rotates while reactants pass through the tube and heat is...
electron-beam lithography system
An electron-beam lithography (EBL) system is a sophisticated nanofabrication tool used in the semiconductor industry and...
rugate
Bearing alternate ridges and grooves; corrugated. Said of some optical surfaces.
center, optical
 lithium niobate
A crystalline ferroelectric material used primarily as a substrate and an active medium for thin-film optical modulators and...
gunsight
An optical device that permits the alignment of a gun, cannon or rocket launcher system with its target.
swept-source laser
A swept-source laser, also known as a wavelength-swept laser, is a type of laser that rapidly and continuously changes its...
jet-streamed dye laser
A continuous-wave dye laser that uses a circulation pump and nozzle to provide an optically flat stream of dye across the...
riez photodiode
A photodiode having a conducting grid that covers the surface of the photodiode junction and intercepts and wastes some of...
compression molding
A method of producing large volumes of plastic optical components in which powdered or sheet plastic is pressed between...
splitting uniformity
When splitting the output of a single optical fiber into two or more fibers, the difference in the maximum loss between any...
optical air mass
A measure of the optical path length for light traveling from the sun or other celestial source through Earth's atmosphere...
strength member
A strand of aramid yarn, steel or fiberglass in an optical cable intended to prevent bending or stretching that would damage...
dig
A cosmetic defect on the surface of an optical element. A dig is nearly equal in terms of its length and width. The size is...
stroboscopic interferometry
A pulsed interferometer that permits the continuous quantitative mapping of the surface deformation of an adaptive optical...
computer-generated hologram
A computer-generated hologram (CGH) is a holographic image produced using computational methods and algorithms, rather than...
longitudinal field modulator
Pockels cell or dynamic optical retarder in which the electrical field is applied in a direction parallel to that of light...
coupling efficiency
The fraction of available output from a radiant source that is coupled and transmitted by an optical fiber.
fiber optic gyroscope
A fiber optic gyroscope (FOG) is a type of gyroscope that uses the interference of light waves to detect changes in...
chuck
In the optical field, a tube to which a lens is fastened for centering.
fusion splice
A splice accomplished by the application of localized heat sufficient to fuse or melt the ends of two lengths of optical...
optical blacking
A light absorbing material applied to ground optical surfaces during the process of making that surface non reflective. Such...
collimation
1. The process of aligning the optical axes of optical systems to the reference mechanical axes or surfaces of an...
launch numerical aperture
The numerical aperture of an optical system used to couple (launch) power into an optical waveguide.
Z-scan
A technique for determining the nonlinear optical properties of a sample material by moving the sample through a focused...
edging
The finishing of the edge of an optical element by grinding.
atomic clock
An atomic clock is a highly precise timekeeping device that uses the vibrations or oscillations of atoms as a reference for...
smart bomb
A bomb guided to its target by some form of electro-optical system.
collimator
An optical instrument consisting of a well- corrected objective lens or mirror with a light source and or object/image (i.e....
rolloff
A defect in the cleaved end face of an optical fiber in which a portion of the edge has broken away; the complement of lip.
mirror coating
One or more thin-film layers of optical material deposited on a mirror blank/substrate in order to enhance the way that...
double-window fiber
Optical fiber capable of operating at both a shorter and a longer wavelength.
optical bistability
The phenomenon that can render an optical resonator the equivalent of a semiconductor flip-flop. A bistable device will...
densitometer
1. An instrument used to measure the opacity or density of dyes, pigments or dispersed particles that form an image in or on...
contour analysis
A method in optical character recognition in which a mobile light beam scans the outlines of characters for subsequent...
resolving power
A measure of an optical system's ability to produce an image which separates two points or parallel lines on the object. See...
soft mold blocking
Blocking by means of a pitch ring, pitch button or a totally pitched block. Pitch, containing a soft filter, may be used...
binary optics
Optical elements, often created by micromachining, lithography or vacuum deposition, that rely on diffraction of the...
stress-applying part
In polarization-preserving optical fibers, the element used to induce birefringence. The SAP is highly doped to provide a...
optical page reader
An optical scanning system found in most computer scanners that can read documents, often in many type styles, and convert...
metallography
The analysis of metal structure using an optical or electron microscope, generally with a camera, to record observations.
fold
1. A flaw in a blank caused by folding the blank's surface during its formation. 2. The change in the direction of a...
fiber-linked array image formatter
A wide-field multiobject spectroscopy system used in astronomy, in which a bundle of low-loss optical fibers positioned on...
laser strainmeter
An instrument usually consisting of a very long interferometer, 3 to 800 m, and a laser light source for the study and...
boule
1. A group of optical fibers that are fused and then treated to produce a vacuum-tight optical fiber cone or plate. 2. An...
image brightness
The apparent luminance of the image as seen through an optical system. This brightness of the image is determined by the...
index profile
In an optical waveguide, the refractive index as a function of radius.
optical coherence tomography angiography
Also known as OCT-A, optical coherence tomography angiography is an imaging technique that uses light waves to measure...
scanning electron microscope
A scanning electron microscope (SEM) is a powerful imaging instrument used in scientific research, materials...
stacked optical memory
A memory system composed of a stack of holographic plates, a mode-locked laser and a rapid detector array. Ultrashort laser...
smart pixel array
An array of active optical devices (modulators, laser diodes and/or detectors), each of whose electrical inputs or outputs...
optical isolator
Also known as an optical diode, an optical isolator is a device that utilizes the Faraday effect to suppress or redirect...
optically isotropic crystal
A transparent crystalline substance that displays the same optical properties (i.e. refractive index) in all directions such...
crosstalk
The measurable leakage of optical energy from one optical conductor to another. Also known as optical coupling.
fluorescent microscope
A type of optical microscope that allows the specimen being viewed to be irradiated by ultraviolet, violet and occasionally...
orthicon
A television camera tube in which a low-velocity electron beam scans a photoactive mosaic that has been created by an...
optics
Optics is the branch of physics that studies the behavior and properties of light, including its interactions with matter...
noncoherent bundle
An assembly of optical fibers that will not transmit coherent images or information because the relationship of the fibers...
reflectance confocal microscopy
Reflectance confocal microscopy (RCM) is a non-invasive imaging technique that allows for high-resolution, in vivo imaging...
coincidence rangefinder
An optical instrument used to determine the distance to a target being viewed. Two similar optical systems view the target...
leaky ray
In an optical waveguide, a ray for which geometric optics would predict total internal reflection at the core boundary, but...
chief ray
The ray that passes through the center of the aperture stop in an optical system. It often is called the principal ray of an...
microcomb
A microcomb, short for microresonator frequency comb, is a novel photonic device that generates a precise series of evenly...
prism
A prism is a geometric optical element with flat, polished surfaces that refract light. It is typically a solid, transparent...
optical instrument dome
A dome-shaped structure used for some optical instruments in place of a flat window. The transparent material should be of...
potassium titanyl phosphate
A crystalline material with a high electro-optic coefficient, capable of operating at short wavelengths, with applications...
figuring
The process whereby the shape of an optical surface is altered by polishing.
Fizeau fringes
Fizeau fringes are interference fringes observed in an interferometer, specifically in a Fizeau interferometer. The Fizeau...
solar furnace
An optical system that is designed to produce a high temperature in a specified area by the optical direction and...
Kerr soliton
A Kerr soliton refers to a specific type of soliton, a self-reinforcing wave packet, that arises in nonlinear optical...
autocollimator
An autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on...
gastroscope
An optical instrument designed for the visual examination of the inside of the stomach.
coded aperture imaging
An imaging process in which the single opening of a simple pinhole camera is replaced with many openings called,...
magnetic enhancement
Plasma-enriched deposition or planar magnetic sputtering that offers increased deposition rates in optical thin-film...
heterogeneous
Property of a substance whose volume elements differ in composition and optical properties.
plastic optical fiber
Plastic optical fiber (POF) is a type of optical fiber made from transparent plastic, typically polymethylmethacrylate...
duplet lens system
An optical system having two sets of components separated by an air space, while successive lenses in each set are cemented...
free-abrasive machining
The process whereby a rotating wheel carries grains of an abrasive, suspended in a vehicle, across the surface of the...
optical constructor
A system of modular mechanical components for building precision optical systems. The basic equipment includes a variety of...
optical sound recorder
 stochastic optical reconstruction microscopy
Stochastic optical reconstruction microscopy (STORM) is a superresolution microscopy technique that enables imaging of...
gallium arsenide injection laser
A laser system consisting of a planar PN junction within a single crystal of gallium arsenide. The pair of parallel,...
Sellmeier's equation
An equation that uses the wavelength of light passing through a medium, along with a set of coefficients, to calculate the...
fluor crown glass
Optical glass that possesses a refractive index equal to or less than 1.5, and an Abbe number that ranges from 62 to about...
striae
An imperfection in optical glass consisting of a distinct streak of transparent material having a slightly different...
optics of material
The area of optics that deals with the interaction of light with a given material. The optical properties of material are...
optical Fourier transform
The optical Fourier transform is a mathematical operation applied to optical signals that involves transforming a spatial...
helium-neon laser
A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates...
image enhancement laser
A semiconductor platelet laser that emits a coherent image by means of plane optical pumping over the platelet surface, and...
Doppler-spread imaging
An imaging process, similar to specific Doppler mapping radar techniques, that utilizes a laser, an optical imaging system,...
averaged threshold receiver
A receiver for optical communications systems consisting of a symmetric binary, pulse-code-modulated transmitter, a...
transfer blocking
A process used to control thickness and parallelism precisely during the production of plane-parallel plates. Elements are...
multichannel spectral analyzer
A spectrometric instrument that detects radiation simultaneously in multiple channels, sorts it spectrally from the deep...
Fizeau interferometer
A type of interferometer noted for producing narrow multiple-beam interference fringes. As a result, when compared with the...
parallax
The optical phenomenon that causes relative motion between two objects when the eyepoint is moved laterally. When parallax...
perovskite
The term perovskite refers to a specific crystal structure commonly found in various materials. Perovskite structures have a...
acousto-optic modulators and deflectors
An acousto-optic modulator (AOM) is a device that utilizes the interaction between sound waves and light waves to modulate...
filter wheel
A device that holds a number of filters and allows the filter with the desired characteristics to be rotated into an optical...
superchromatic correction
Correction of an optical system at four separate wavelengths. This correction, longitudinal and lateral, is possible with...
holographic microscopy
The holographic recording of a microscopic specimen whereby magnification is achieved by alteration in a wavelength or...
focal length
The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or...
electrostatic image dissector
A nonmagnetic instrument utilizing an electrofocus and deflection tube with a photocathode for imaging purposes. The optical...
signal-induced noise
Noise generated in the flow of current in the photomultiplier, produced by the intentional or controlled application of...
differential mode delay
A variation in propagation delay caused by differences in group velocity among modes of an optical fiber. Also called...
optical path
crystal
A solid with a structure that exhibits a basically symmetrical and geometrical arrangement. A crystal may already possess...
Prentice's rule
A method of determining prism power at any point on a lens. Prism power equals the product of the dioptric power and the...
conoscope
An optical instrument, generally a polarizing microscope, that is used to determine the interference figures and optical...
radial distortion
An alteration in magnification from the center of the field to any point in the field, measured in a radial direction from...
splice
A permanent joint whose purpose is to couple optical power among two or more ports. Also, a device whose purpose is to...
optical combiner
An optical combiner, in the context of optics and display technologies, refers to a device or component that combines...
beam shaper
A beam shaper is an optical device or system designed to modify the spatial profile or intensity distribution of a laser or...
working distance
In microscopy, the clear distance between the specimen being viewed and the first optical element of the objective lens.
block
A supporting member used to hold optical parts during grinding and polishing. It also describes the assemblage of optical...
channel density
The number of channels per unit bandwidth handled by a single optical fiber.
parametric oscillator
A device using a parametric amplifier inside a resonant optical cavity to generate a frequency-tunable coherent beam of...
fiber-lens fusing
A method of terminating optical fibers by forming a lens directly on the end of the fiber, eliminating the need for precise...
allogyric birefringence
Left- and right-hand circularly polarized beams that are produced at different velocities by passing plane-polarized light...
diffraction limited
The property of an optical system whereby only the effects of diffraction determine the quality of the image it produces.
angular misalignment
Angular deviation from the optimum alignment of source to optical waveguide, waveguide to waveguide, or waveguide to...
laser cavity
A laser cavity, also known as an optical cavity or resonator, is a fundamental component of a laser system. It is a confined...
Pockels
In optics, the Pockels effect refers to the phenomenon where the refractive index of a material changes in response to an...
hybrid cable
A cable assembly containing both optical fibers and copper electrical conductors in the same jacket.
optical aberration
 image optics
Any form of lens, optical system (camera, telescope, microscope, etc.), or opto-electronics utilized for the purpose of...
slicing and cutting machines - for crystals, quartz, glass, etc.
A crystal, glass, or quartz slicing and cutting machine is a specialized piece of equipment used in the manufacturing...
coated optics
Optical elements that have been coated with one or more layers of dielectric, or metallic material. These coatings serve to...
fused silica
Glass consisting of almost pure silicon dioxide (SiO2). Also called vitreous silica. Frequently used in optical fibers and...
drawing tower
A system for fabricating optical fiber, consisting of a furnace that heats the materials, a polymer coating stage, a...
optical continuous wave reflectometer
An instrument used to measure backscatter as well as optical return loss and reflectance within an optical fiber system by...
Mach-Zehnder interferometer
A Mach-Zehnder interferometer is an optical device used to measure the phase difference between two collimated beams of...
Mie scattering
Mie scattering, named after the German physicist Gustav Mie, refers to the scattering of electromagnetic radiation (such as...
slab interferometry
The method for measuring the index profile of an optical fiber by preparing a thin sample that has its faces perpendicular...
nonlinear optics
Nonlinear optics is a branch of optics that studies the optical phenomena that occur when intense light interacts with a...
plastic-clad silica fiber
An optical waveguide having a silica core and a plastic cladding.
enclosed laser device
A laser or laser system positioned within an enclosure to prevent dangerous optical radiation from leaving the enclosure.
edge thickness difference
The maximum variation in thickness of a lens as measured around a diameter centered on the optical axis. The ETD divided by...
precision aperture
An accurately produced hole of any size and shape that is used as a masking device in an optical system. Pinhole apertures...
dichroism
Dichroism refers to the property of certain materials to exhibit different colors or absorbance of light depending on the...
dynamic magneto-optical correlator
An optical correlator incorporating a binary phase-only spatial light modulator made from an iron garnet magneto-optic solid...
transducer
A transducer is a device or component that converts one form of energy into another. It is commonly used in various fields,...
leaky mode
In an optical waveguide, a mode whose field decays monotonically for a finite distance in the transverse direction but which...
direct detection
In a fiber optic transmission system, the conversion of received optical pulses directly to an electrical signal.
ion exchange technique
A method of fabricating a graded-index optical waveguide by means of an ion exchange process.
piezo-optical transducer
A structure consisting of a thin film of liquid crystal sandwiched between light-polarizing filters that have received a...
homogeneous
That property of a substance that determines that all components of volume are the same in composition and optical...
optical maser
bubble chamber
A large tank filled with liquid hydrogen, with a flat window at one end and complex optical devices for observing and...
oculometer
An electro-optical infrared tracker consisting of a beamsplitter, an illuminating source, an image dissector tube and an...
heterodyning
In optical communications, the translation of optical signals into radio signals, lowering their frequency in detection from...
scattered light filter
A specific type of filter designed to reduce the amount of light scattered by reflections from the edges of optical...
beam expander
A system of optical components designed to increase the diameter of a radiation beam. Usually an afocal system.
matrix unit
An electrical or optical device used to convert color coordinates.
pressurization
Injecting a gas (usually nitrogen) with a very low moisture content into the body of an optical instrument to create a...
null lens
A lens used in the optical testing of an aspheric surface. It converts a spherical wavefront into one that precisely matches...
volumetric imaging
Volumetric imaging refers to the capture, visualization, and analysis of three-dimensional (3D) information from a volume of...
lambertian emitter
An optical source that has a luminous distribution that is uniform for all directions.
cladding
The low-refractive-index material that surrounds the core of an optical fiber to contain core light while protecting against...
interferometer
An instrument that employs the interference of lightwaves to measure the accuracy of optical surfaces; it can measure a...
optical extent
Mathematically defined as the product of etendue (or throughput) and the square of the refractive index, the optical extent...
point-probing scanning optical microscope
fused array of fibers
Optical fibers fused together to form a solid, vacuum-tight assembly in the form of a slab or rod. Discs or rectangular...
stadimetry
The determination of distance based upon the known size of an object and the size of its image at the image plane of an...
double-crucible method
A method of fabricating an optical waveguide by melting the core and clad glasses in two suitably joined concentric...
modulation transfer function
Also called sine wave response and contrast transfer function. The modulation transfer function is the ratio of the...
laser designator
A laser device used to establish a location or target usually for detection by an impact source e.g. missiles and guided...
jacket
The outer material that surrounds and protects the buffered and unbuffered fibers in an optical cable.
optical phase distortion
Optical phase distortion refers to a phenomenon where the phase of an optical wavefront is altered as it propagates through...
optical cavity
wedge spectrograph
A spectrograph in which the flux density transmitted through the entrance aperture is regulated by an optical wedge or...
fluorescence microscopy
Fluorescence microscopy is a specialized optical imaging technique used in biology, chemistry, and materials science to...
laser drift
Laser drift typically refers to a phenomenon where the frequency or wavelength of a laser source gradually changes over...
impurity level
In the context of optical materials, the term "impurity level" refers to the presence of foreign atoms or molecules within...
STED microscopy
STED microscopy, or stimulated emission depletion microscopy, is a superresolution imaging technique in fluorescence...
chromatic aberration
Chromatic aberration is an optical phenomenon that occurs when different wavelengths (colors) of light are refracted by a...
fiber optic lightguide
A bundle of optical fibers arranged randomly for the purpose of transmitting energy, not an image.
optical component
One or more optical elements – typically cemented together - in an optical system that are treated as a single group;...
atmospheric turbulence
Irregularities and disturbances in the atmosphere that are of particular interest because they induce random temporal and...
MTF optimization
Computerized lens design algorithm that permits the lens MTF characteristic to be included and controlled during the...
optical manufacturing tools and machinery
Optical manufacturing tools and machinery encompass a wide range of equipment, instruments, and systems used in the...
electro-optic shutter
A device used to control or block a light beam by means of the Kerr electro-optical effect.
Porro prism erecting system
The arrangement of two Porro prisms so that the inverted image formed by certain types of optical instruments is the same as...
holographic camera
A holographic camera, also known as a holographic imaging system or holographic recorder, is a specialized device used to...
compensator
An optical element that measures the phase difference between two components of elliptically polarized light to correct for...
segmentation
In optical character recognition, the method of dividing a string of characters into separate, distinct characters.
polarization dependent loss
In passive optical components, loss that varies as the polarization state of the propagating wave changes. Expressed as the...
optical blank
A casting consisting of an optical material molded into the desired geometry for grinding, polishing or, in the case of...
axial gradient
In gradient index optics, a gradient profile in which the refractive index varies along the direction of light propagation,...
passive optical component
A device that responds to incident light but does not generate light.
machine vision lens
A machine vision lens is a specialized optical lens designed for use in machine vision systems, which are used for automated...
diffractive lens
Any optical device that utilizes diffraction in an image-forming capability. Familiar diffractive lenses are zone plates,...
hackle
A defect in the cleaved end face of an optical fiber, defined as multiple surface irregularities across the fiber surface. A...
grain isolating diaphragm
In a microscope, the diaphragm located between the Bertrand lens and the eyepiece, which is closed during conoscopic viewing...
direct viewfinder
A viewfinder whose optical system forms a direct image of a subject, as opposed to those systems that use reflectance in the...
spatial light interference microscopy
Spatial light interference microscopy (SLIM) is an optical microscopy technique that belongs to the category of quantitative...
true field
The size of the field of view in the object space of an optical system as differentiated from that in the image space...
fiber-coupled photoconductive antenna
A fiber-coupled photoconductive antenna (FCPA) is a type of optoelectronic device that combines a photoconductive antenna...
polycarbonate
A tough, durable, heat- and cold-resistant optical quality plastic used in injection-molded items such as streetlight...
integrated optical circuit
An optical circuit, either monolithic or hybrid, composed of active and passive components, used for coupling between...
Q-switch
A device used to rapidly change the Q of an optical resonator. It is used in the optical resonator of a laser to prevent...
detem
A device in which the functions of optical detector and emitter are combined.
linear receive optics
Linear receive optics typically refers to the optical components and systems used in the reception (detection) of linearly...
constant deviation
That property of certain optical devices, e.g., a penta prism, that maintains the angular relationship between the entering...
bay
In optical character recognition, a feature at the boundary of a character.
optical storage
apochromatic system
An optical system that is corrected chromatically for three colors simultaneously.
millidiopter
A unit of metric measure equivalent to 1 thousandth (or 10-3 ) of the standard unit of optical power which is the diopter (1...
photodetector
A photodetector, also known as a photosensor or photodiode, is a device that detects and converts light into an electrical...
quantum confinement
Quantum confinement refers to the phenomenon in quantum mechanics where the motion of charge carriers, such as electrons or...
aerial perspective
An optical illusion in which distant objects are lighter in tone and less distinct in outline than those closer to the...
profile dispersion
In an optical waveguide, that dispersion attributable to the variation of refractive index profile with wavelength. The...
phase matching
Phase matching is a crucial concept in the field of optics, particularly in nonlinear optics and the generation of coherent...
attenuation coefficient
The rate of diminution of average optical power and the sum of the scattering and absorption coefficients.
laser diode module
A laser diode module is a compact device that incorporates a laser diode, optics, and often other components into a single...
optical thickness
The physical thickness times the refractive index.
fiberscope
An optical instrument consisting of an objective lens, a coherent (usually flexible) fiber bundle and an eyepiece to examine...
cement
An adhesive used for bonding optical elements or for holding devices.
reticle
A reticle, also known as a reticule or graticule, is a pattern or set of markings placed in the focal plane of an optical...
superradiance
Directional and coherent radiation pulses that result from an ensemble of coherently prepared states in an optical medium.
fiber Bragg grating
A fiber Bragg grating (FBG) is a type of optical filter that is inscribed or "written" into the core of an optical fiber. It...
micro-optics
Micro-optics refers to the design, fabrication, and application of optical components and systems at a microscale level....
Faraday rotation
The effect discovered by Faraday in 1845 whereby nonoptically active materials or substances become capable of rotating the...
tissue optics
The study of the optical properties of living tissue. Increased understanding of the behavior of light in this varied,...
GaN distributed feedback lasers
GaN (gallium nitride) distributed feedback (DFB) lasers refer to a specific type of semiconductor laser based on Gallium...
lenticular
An array or mosaic of optical surfaces. May be a number of lenses closely packed to form multiple images or many parallel...
concave
Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In...
wave optics
Also referred to as physical optics - the area of optics in which the wave nature of light is essential when defining its...
resonator
A resonator is a device or system that exhibits resonance, which is a phenomenon that occurs when an external force or...
image motion compensation
The active control of various aspects (optical element position, airspace thickness, etc.) of an optical system that...
custom optic
A custom optic refers to an optical component that is designed, manufactured, and tailored to meet specific requirements or...
insertion loss
The total optical power loss caused by the insertion of an optical component such as a connector, splice or coupler into a...
optically coupled isolator
 Abbe-Porro prism
A reflecting prism that inverts the image. The image is reflected four times internally and emitted laterally. The prism is...
phase screen
A phase screen, in the context of optics and wave optics, refers to a surface or medium that introduces a phase delay to an...
deeply depressed cladding fiber
An optical fiber, usually a single-mode fiber, that has an outer cladding with nearly the same index of refraction as the...
fluorescence decay system
A device, also called a fluorescence lifetime instrument, that measures decay curves of fluorescing samples. It generally...
stacked-diode laser
A type of laser used when a great amount of power is required. Avoiding the bulk of large numbers of optical lenses, this...
vertical air photograph
An aerial photograph produced when the optical axis of the camera is perpendicular to the surface below.
self-phase modulation
Self-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a...
ruby laser
The optically pumped, solid-state laser that uses sapphire as the host lattice and chromium as the active ion. The emission...
photometry
Photometry is the branch of science that deals with the measurement of light, particularly in terms of its intensity and the...
ultrasonic detector
A mechanical, electrical, thermal or optical detector designed to identify and measure ultrasonic radiation.
Fresnel reflection
Fresnel reflection refers to the reflection of light at the interface between two different media with different refractive...
fiber lapping
A method of optical fiber coupling in which the fibers are ground down to expose their cores and placed together to allow...
clear aperture
The limited light-gathering area of an optical system. The area is normally restricted to an edge or outer surface of an...
dispersion-shifted fiber
A dispersion-shifted fiber (DSF) refers to a type of optical fiber designed to minimize the effects of chromatic dispersion,...
stimulated Brillouin scattering
In Stimulated Brillouin Scattering (SBS), an incident photon (usually laser light) interacts with acoustic phonons in a...
broadband dielectric mirrors
Broadband dielectric mirrors, also known as broadband mirrors, are optical coatings designed to efficiently reflect or...
optical correlator
A device incorporating a spatial light modulator and a reference filter; used for matching an input optical waveform or...
optical cements and adhesive
Optical cements and adhesives are specialized materials used in the assembly and bonding of optical components in optical...
aberration
A departure from ideal paraxial imaging behavior. The distortion of an optical field wavefront as it is propagated through...
far-infrared laser
A laser with output over a wide range of wavelengths spanning the far-infrared region of the spectrum (30 to 1000 µm);...
optical trapping
molecular motor
A molecular motor refers to a nano-sized device composed of organic molecules or other small-scale components that can...
measuring wedge
A wedge in a rangefinder or heightfinder used to displace the image produced by one telescope so that it coincides with that...
computer vision
Computer vision enables computers to interpret and make decisions based on visual data, such as images and videos. It...
optical work
The degree to which the surface of a lens causes an incident ray of light to bend, or the amount of convergence or...
optical
Pertaining to optics and the phenomena of light.
crush strength
The physical limit of an optical fiber or cable to withstand an applied force or weight perpendicular to the axis of the...
plasma chemical vapor deposition
The use of a plasma to induce the formation of oxides in the production of graded-index optical fibers.
milling
An automatic surface-generating process involving the removal of a material from a given surface. Optical milling typically...
light valve
With respect to display systems, a device that uses an independent light source and a control-layer medium, the active...
objective
The optical element that receives light from the object and forms the first or primary image in telescopes and microscopes....
lip
A defect in the cleaved end face of an optical fiber, in the form of a sharp protrusion at the edge of the fiber.
optical comparator
Typically used for the examination of manufactured or engineered parts, an optical gauging device, in which a backlight is...
abridged spectrophotometer
An instrument that uses optical filtration in order to measure the transmittance for a discrete range or specific number of...
barrier layer
In the fabrication of an optical fiber, a layer that can be used to create a boundary against OH-ion diffusion into the core.
Baker-Nunn camera
A wide-field camera based on the classic Schmidt optical system used to photograph Earth-orbiting satellites.
grating monochromator
An optical instrument used to isolate a narrow bandwidth of optical radiation using a diffraction grating as the dispersive...
magnetorheological finishing
Magnetorheological finishing (MRF) is a precision optics polishing technique used for shaping and finishing optical surfaces...
photochemical hole burning
A method of producing disks for erasable optical data storage. Information is recorded by a laser beam that generates pits...
phase-change optical disc
An erasable data recording and storage medium that uses a laser to heat the crystalline surface of the disc to a certain...
free-space optical interconnect
A type of internal photonic connection in an integrated circuit in which a holographic grating is used to focus light at...
alignment telescope
An optical tooling instrument consisting of an objective lens, a focusing lens, an optical micrometer, a reticle and an...
sign conventions
A convention that defines specific dimensions of an optical system, such as the image distance or radius of curvature of a...
amplifier
A device that enlarges and strengthens a signal's output without significantly distorting its original waveshape. There are...
eyepiece
Also known as ocular. The lens system used between the final real image in a visual optical system and eye. It acts as an...
high harmonic generation
High harmonic generation (HHG) refers to a nonlinear optical process in which intense laser light interacts with a gaseous...
optically active material
A material that can rotate the polarization of light that passes through it. An optically active material exhibits different...
accumulator
A broadband continuum resonator that confines a wide range of wavelengths. From the optical confinement a single wavelength...
blocking cement
An adhesive used to hold optical elements to blocking tools. It is usually a thermoplastic substance such as resin, beeswax,...
direct read after write
A write-once optical disc storage system in which the optical head reads continuously while writing to check the accuracy of...
self-electro-optic effect device
An optically bistable device used for photonic switching, constructed of a multiple quantum well biased by an external...
slurry
The name of the mixture of liquid and grinding or polishing compounds used in processing optical materials.
auxiliary telescope
A low-power telescope placed at the eyepiece of an optical system to increase overall magnification. Most often used to...
adaptive deconvolution
The process of adjusting input pixel by pixel at the filter plane to adapt to nondeal phase behavior in an optical...
exit angle
The angle between a light ray emerging from an optical system and the optical axis of that system.
multiplexing
The combination of two or more signals for transmission along a single wire, path or carrier. In most optical communication...
transmission loss
The decrease in power that occurs when an optical beam or signal is transmitted through a system.
b integral
Calculates the exponential growth of the least stable spatial frequency in a laser beam, and is the numerical equivalent of...
centering
1. Mounting a lens or mirror so that its optical axis is coincident with the optical or mechanical axes of other portions of...
green block
A porous ceramic substance that is ground to a given optical form and on which a polished plate of glass is sagged by heat...
blur circle
A 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...
three-photon microscopy
Three-photon microscopy is an advanced imaging technique that belongs to the family of multi-photon microscopy methods. It...
two-photon excited fluorescence
Two-photon excited fluorescence (TPEF) is a nonlinear optical method that allows imaging of biological cells and living...
chirped-pulse amplification laser
A laser whose pulses are expanded, using gratings and optical fibers, before amplification and compressed to increase beam...
exciter lamp
A small incandescent lamp whose intense beam is focused on the optical soundtrack of a motion picture film. The soundtrack...
diamond cutting tool
A tool made by imbedding small particles of diamond in the working edge. In the optical field, the most commonly used...
lensometer
An ophthalmic instrument used to measure the magnitude and direction of the maximum and minimum powers of a spectacle lens,...
optical staining
With respect to microscopy, also called dispersive staining, optical staining the projection of colors through areas of a...
APD detector
An APD detector, or avalanche photodiode detector, is a type of photodetector used to detect light or optical signals by...
meridional ray
A ray that lies in the meridional plane; a ray that lies in the plane that contains the optical axis. A tangential ray.
Sagnac interferometer
A type of interferometer in which two coils of optical fiber are arranged so that light from a single source travels...
monocoil sheathing
A type of tubing used to protect optical fiber cables, consisting of a wire spiral of aluminum, galvanized steel or...
automatic optical inspection
A system for automatic industrial process control or measurement, consisting of an optical module for image acquisition, a...
correction window
An optical wedge of very small angles that admits light while sealing out moisture and dirt and that may be rotated to...
scanner
1. 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...
intermediate image
In an optical system with a series of lenses, images formed prior to the final focal plane.
step index fiber
An optical fiber in which the core is of uniform refractive index.
laser microscopy
Technique using functional optical microscope with the addition of a coherent source collinear with the image path. The...
Czerny-Turner design
A form of monochromator optical system consisting of two spherical concave mirrors used in conjunction with a movable...
axial vapor-phase deposition
A vapor-phase oxidation process for fabricating graded-index optical fibers. It differs from outside vapor phase deposition...
endoscope
An endoscope is a medical device used for visualizing and examining the interior of hollow organs, body cavities, or...
tangential distortion
Optical aberration such that image magnification varies with ray distance from the optical axis in a radial distortion.
YAG crystal
A YAG crystal refers to a solid-state crystal made of yttrium aluminum garnet (YAG), which is a synthetic crystalline...
concatenation
The process of linking optical fiber end to end.
gallium nitride
Gallium nitride (GaN) is a compound made up of gallium (Ga) and nitrogen (N). It is a wide-bandgap semiconductor material...
elasto-optic effect
A change in the refractive index of an optical fiber caused by variation in the length of the fiber core in response to...
open optical interface
An interface in an optical network that permits an optical signal to pass without changing the optical signal to an...
integrated optics
A thin-film device containing miniature optical components connected via optical waveguides on a transparent dielectric...
copying camera
A camera mounted on an optical bench with an easel to hold the material to be copied. Magnification can be varied over a...
optical rangefinder
 photoemulsion
In photolithography, an opaque material used in masks that has a lower optical density and grainier composition than chrome.
connector loss
Energy loss encountered at connectors in optical fiber transmission systems. The major contributors are mutual core...
optical noise
Optical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or...
mode filter
A device used in measuring the attenuation of multimode optical fibers. A short reference length of fiber when combined with...
optical coherence tomography
Optical coherence tomography (OCT) is a non-invasive imaging technique used in medical and scientific fields to capture...
guided ray
In an optical waveguide, a ray that is completely confined to the core.
optical cable assembly
An optical cable that is connector terminated. Generally, an optical cable that has been terminated by a manufacturer and is...
light throughput efficiency
The fraction of incident light power in an optical modulator that is available to the output beam.
unblocking
The process whereby optical elements are removed from a block.
Matrix optics
The linear relationship between input and output optical fields for a given optical system or application that allows the...
clear eye distance
In a visual optical system, the axial distance from the last mechanical surface of the eyepiece to the exit pupil.
nonlinear optical effect
A class of optical phenomena that can be viewed only with nearly monochromatic, directional beams of light, such as those...
dirt hole
A hole filled with dirt such as a polishing abrasive and located in an optical surface. See dig; scratch.
Kerr effect
The Kerr effect, named after the physicist John Kerr who first observed it in 1875, is a nonlinear optical phenomenon where...
slide projector
An optical projection device designed to project positive color transparencies onto a screen for viewing.
signal level
Calculation of peak and average transmission power at a given point along an optical fiber or cable.
microenvironmental control system
Equipment that supports microscopic live-cell imaging by managing the gas, media perfusion, temperature and other factors to...
optical modulator
A multilayered thin-film device used to modulate transmitted light in integrated photonic circuits.
optical barcode reader
An optical barcode reader, commonly known as a barcode scanner, is a device that uses optical technology to capture and...
quantum noise
Noise generated within an optical communications system link that has both internal (dark current) and external (background...
optical grating reflectance evaluator
A device for measuring diffraction grating efficiency at any angle of incidence, consisting of a reflectometer wherein the...
octave
In optics, an octave typically refers to a range of frequencies or wavelengths that spans a factor of 2. In other words,...
annealing furnace
An oven or furnace that possesses the design requirements and heat control necessary to anneal glass for the optical...
gap loss
The optical power loss caused by a space between axially aligned fibers.
infinity space
In a microscope, a space reserved to accommodate an optical filter or polarizer.
fused quartz and silica
Fused quartz and silica are closely related materials, both composed primarily of silicon dioxide (SiO2), but they are...
curing
The use of chemicals or radiation to induce a desired change in a substance; e.g., some optical adhesives are set by...
contextual analysis
In optical character recognition systems, the identification of a character facilitated by means of known factors governing...
mirror testing
The observation and measurement of the flatness of a mirror surface by contacting an optical flat with the mirror. The...
negative ghost
A ghost image that has the reverse lightness relations of the original image. This phenomenon is a common optical illusion...
optical activity
The capacity of a chiral substance such as a crystal or molecule to rotate the plane of polarized light that is transmitted...
refracted ray
A light ray that has had its direction altered because of its traversing an air-to-glass interface at some angle. In an...
pseudohologram
Coded image obtained optically with a nonredundant pinhole array imaging aperture.
flip chip
An optical switch that controls conduction paths into and out of a junction in fiber optic and integrated optical circuits.
real image
An image that is formed when rays emerging from an optical system all converge to a point on the optical axis. A real image...
laser pattern generation
Production of a repeated image of a transmitted beam through a diffractive optical element such as a holographic card or...
quasi-optical
Having properties resembling those of light- waves; e.g., the propagation of waves in the television spectrum.
damped least squares
An organizational method used in optical design computer programs. The technique produces one number (merit function) to...
sol-gel
A gelatinous fluid that can be used as a porous thin-film coating for optical components, including laser beam collimators,...
optical computer
 hot extrusion
A method of manufacturing polycrystalline infrared-transmitting optical fiber by heating a single halide crystal billet and...
veiling glare
Diffuse stray light at the image plane of an optical system that results in reduced contrast and resolution.
diffractive optics
Optical elements that use diffraction to control wavefronts. Diffractive optical elements include diffraction gratings,...
transmitter
In fiber optic communications, a light source whose beam can be modulated and sent along an optical fiber, and the...
chip
1. A localized fracture at the end of a cleaved optical fiber or on a glass surface. 2. An integrated circuit.
binocular parallax
The difference in angular bearing of an object as seen by the two eyes, due to the separation of the visual optical axes.
circular birefringence
The optical phenomenon in which right circularly polarized light transmitted by an active medium travels at a different...
refracted ray method
The technique for measuring the index profile of an optical fiber by scanning the entrance face with the vertex of a high...
integral density
With respect to color photography, the measurement of the way the color film modulates the radiant flux in the optical...
optical spectrum
1.) Generally, the electromagnetic spectrum within the wavelength region extending from the vacuum ultraviolet at 40 nm to...
optoelectronic
Pertaining to a device that responds to optical power, emits or modifies optical radiation, or utilizes optical radiation...
grinding tool
A tool of cast iron or another suitable medium used with a slurry of silicon carbide, aluminum oxide or emery for grinding...
optical contact
The adhesion of two sufficiently clean and close-fitting surfaces without the use of cement or glue. The optically contacted...
fiber laser
A fiber laser is a type of laser in which the active gain medium is an optical fiber doped with rare-earth ions such as...
critical aperture
In an optical system, the aperture size at which the lens gives its best overall performance.
Fabry-Perot cavity
An optical resonator in which feedback is accomplished by two parallel planes. In diode lasers, the planes are obtained by...
edge-emitting LED
An edge-emitting light-emitting diode is a type of LED structure where light emission occurs primarily along the edge of the...
diaphragm
A flanged or plain ring with a restricted aperture, located in an optical system at any of several points, that cuts off...
axial paraxial ray
A paraxial light ray that extends from an object point on the optical axis.
microbubble resonator
A microbubble resonator is a device used in photonics and optical physics for the precise manipulation of light waves. It...
entrance slit
The entrance slit, also known simply as the slit, is an essential component in optical instruments such as spectrometers and...
laser crystal
A laser crystal, also known as an active medium or gain medium, is a solid-state material used in the construction of...
image
In optics, an image is the reconstruction of light rays from a source or object when light from that source or object is...
Fresnel reflection loss
Reflection losses incurred at input and output of optical elements because of the difference in refractive index between...
fiber axis
The mechanical centerline through the core of an optical fiber.
relative intensity noise
The inherent laser amplitude noise relative to the average optical power produced by the laser; the RIN decreases rapidly as...
wedge
An optical element having plane-inclined surfaces. Usually the faces are inclined toward one another at very small angles....
optical waveguide
Any structure having the ability to guide the flow of radiant energy along a path parallel to its axis and to contain the...
polygonal mirror
A polygonal mirror, also known as a multifaceted mirror or facet mirror, is a type of optical component used in various...
spectral integral density
With respect to color photography, the measurement, at a given wavelength, of the way the color film modulates the radiant...
transverse offset method
A technique used to measure the mode-field diameter of an optical fiber by scanning one fiber past another at a distance of...
optical autocorrelator
An instrument used to test lenses by utilizing the optical transfer function. It consists of a HeNe laser, a beamsplitter...
optical grating
An optical grating, in the context of optics and physics, refers to a device with a periodic structure of closely spaced,...
ion laser
A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized...
source efficiency
The ratio of emitted optical power of a source to the input electrical power.
adaptive optics
Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of...
zirconium fluoride
An infrared transmitting material used in the production of fluoride glasses for optical fibers.
image amplifier
An electro-optic system using, in general form, an evacuated glass envelope with a semitransparent photocathode at one end...
heightfinder
A rangefinder used to determine the height or altitude of aerial targets by means of optical triangulation. The device...
relay lens
A lens or lens system used to transfer a real image from one point within an optical system to another, with or without...
image transducer
Any arrangement of a bundle of optical fibers that alters the shape of the image. For example, by systematic regulation of...
Photoelastic equipment and supplies
Photoelastic equipment and supplies refer to instruments and materials used in photoelasticity, a technique used to analyze...
vertical leveling mirror
A two-sided mirror suspended by a pendulum mechanism. An autocollimator set normal to such a mirror surface will, by...
swept source optical coherence tomography
Swept-source optical coherence tomography is an imaging technique used in medical diagnostics, particularly in...
fiber bandwidth
The lowest frequency at which the magnitude of the fiber transfer function decreases to a specified fraction of the zero...
pyramid error
Pyramid error in optics refers to an aberration in the shape of an optical surface, particularly in the context of mirrors....
femtosecond laser
A femtosecond laser is a type of laser that emits ultrashort pulses of light with durations on the order of femtoseconds,...
far-field diffraction pattern
The diffraction pattern of a source such as a light-emitting diode, injection laser diode or the output end of an optical...
optical dummy
1. A lens formed to a desired curve and used to form a polisher. 2. A piece of glass included in a block to fill out the...
optical transform image modulation
A technique for detecting and measuring atmospheric pollution, in which an oscillating mirror directs half the incoming...
second-harmonic generation
Second-harmonic generation (SHG) is a nonlinear optical process that occurs when two photons with the same frequency combine...
hard-clad silica fiber
A type of optical fiber in which a silica core is surrounded by a hard polymer or similar material much stronger than the...
laser dazzle system
Visible laser radiation, often optically expanded and collimated, used to induced temporary blindness from within a walking...
polyvinyl alcohol
An optical-quality polymer used in birefringent retarders.
paraxial ray
A ray that behaves according to paraxial equations; one that lies close to and almost parallel to the optical axis.
corner cube
A corner cube, also known as a corner reflector or retroreflector prism, is a type of optical device used to reflect light...
MSM photodiode
A metal-semiconductor-metal (MSM) photodiode is a type of photodetector that consists of metal electrodes on a semiconductor...
ultraviolet fiber optics
Ultraviolet (UV) fiber optics refers to optical fibers that are designed and optimized for the transmission of ultraviolet...
off-axis paraboloid and ellipsoid mirror
Off-axis paraboloid and ellipsoid mirrors are specialized optical components used in various optical systems, particularly...
lenticular screen
A rear or front projection screen composed of minute optical surfaces that introduce a spread to the light beam that...
diffuser
An optical diffuser is an optical component or material designed to scatter or diffuse light that passes through it. It is...
mass spectroscope
An instrument that uses electromagnetic fields to sort out the relative masses of atoms and molecules.The same way an...
optical gate
An optical gate typically refers to a device or system that controls the transmission of light, allowing it to pass through...
calcite interference microscope
A microscope that allows examination of a small crystal and conveniently provides linearly polarized object and reference...
optical head
In compact disc and CD-ROM technology, the portion of the drive that projects the laser light onto the surface of the media...
Ritchey-Common test
An interferometric method for describing the surface shape of large coated or uncoated optical flats. The procedure uses a...
optical nonlinearity
The phenomenon that makes nonlinear the mathematical expression for the electrical polarization of a medium through which...
polarimetric analysis
The determination of a substance's identity or quantity through the analysis of its optical rotation. For example, the...
buffer
1. In fiber optics, a protective material applied as an optical fiber cover that has no optical function. 2. In image...
III-V material
In semiconductor physics and materials science, the term "III-V materials" refers to compounds composed of elements from...
serpentine bend mode filter
A device used in measuring attenuation in optical fiber. The loss caused by the bends in a short reference length of fiber...
low-loss fiber
Optical fiber that transmits a greater percentage of input light than does high-loss step-index fiber. Low-loss fiber...
free-space optics
Free-space optics (FSO), also known as optical wireless communication or optical wireless networking, refers to the...
bacteriorhodopsin
A light-harvesting protein found in the purple membrane of a micro-organism called Halobacterium halobium. The protein...
protective bevel
The removal of a sharp edge on an optical element by grinding, to prevent accidental chipping of that edge during subsequent...
phase mask
In optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it....
orthonormalization
Optimization method used in optical design computer programs that employs a variable-by-variable approach to construct new...
decentration
In a single element, any lack of coincidence between the optical and the mechanical axes. In a lens system, any lack of...
static fatigue
The application of a constant stress to an optical fiber.
microcircuit manufacturing
The formation of transistors, diodes, capacitors, resistors and other electronic elements directly on a flake of silicon by...
beamsplitter
A beamsplitter is an optical device for dividing a beam into two or more separate beams. A simple beamsplitter may be a very...
optical multimeter
An instrument that measures several optical parameters, such as optical power and wavelength, with a single measurement...
core
The light-conducting portion of an optical fiber, defined by the region of high refractive index.
multifibers
An array of optically distinct fibers that are fused into one strand. They are used to keep the resolution efficiency of the...
abrasion mark
Optical surface damage due to abrasive rubbing. Abrasion damage affects are less than the thickness of the optical coating...
loss budget
The total optical power loss in a system. The loss budget is often stated in terms of the transmitted power and the power...
atom optics
The area of optics in which the wave nature of a particle is exploited to carry out very accurate interferometry and other...
mesoscope
In the field of optics and imaging, a mesoscope refers to an optical instrument that is designed to observe and capture...
optofluidics
Optofluidics is an interdisciplinary field that combines principles from optics and fluidics to create devices and systems...
anisotropic
Anisotropic is a term used to describe a material or substance that exhibits different properties or behaviors in different...
paraxial
Characteristic of optical analyses that are limited to infinitesimally small apertures. Also called first-order or Gaussian...
entrance pupil
In a lens or other optical system, the image of the aperture stop as seen from object space.
electrolytic shutter
A high-speed shutter, similar to a Kerr cell, that uses the birefringence produced in a liquid during the passage of an...
CD-ROM (compact disc read-only memory)
An adaptation by Philips and Sony of their audio compact disc technology for optical disc data storage and retrieval....
InGaAs photodiode
An InGaAs photodiode refers to a photodetector device that is constructed using a semiconductor material composed of a...
microelectromechanical systems
Refers to micron-size complex machines that have physical dimensions suitable for the fabrication of optical switches for...
photoelectric mixing
Also known as light beating. The mixing of two narrowband optical components to produce an AC component in the photocurrent...
optical repeater
In an optical fiber or waveguide communications system, an optoelectronic device or module that receives an optical signal,...
optical rail
graded index
Descriptive of an optical fiber having a core refractive index that decreases almost parabolically and radially outward...
infrared light-emitting diode
An infrared light-emitting diode (IR LED) is a semiconductor device that emits infrared light when an electric current...
photoelastic constant
A formulaic description of the linear change of the reciprocal optical dielectric tensor with either stress or strain.
regenerative amplifier
A type of multiple-pass amplifier in which no optical leakage is allowed until a finite number of passes has occurred; at...
front-surface mirror
An optical reflector with the reflective coating applied to the front surface of the substrate. This eliminates the ghost...
galvanometric scanner
A galvanometric scanner, also known as a galvanometer scanner or galvo scanner, is a type of optical scanning device used to...
electrocapillarity modulator
A type of optical modulator with potential application in optical switching and displays, in which applied voltage causes a...
prism coupler
An instrument that measures the angle at which a prism can couple laser light into an optical waveguide; used to determine...
photoconductor contact
Material used to integrate photoconductors into electro-optical systems. It should provide low resistance to the flow of...
GRIN lens
A GRIN (gradient index) lens is a type of optical lens that utilizes a gradient in refractive index across its volume rather...
section converter
An arrangement of optical fibers in a bundle whereby the geometric configuration of the input end differs from that of the...
relative aperture
The ratio of the diameter of the entrance pupil in an optical system to the equivalent focal length of that system. The...
optical glass
Optical glass refers to a type of glass specifically engineered and manufactured for use in optical components and systems,...
enantiomer
A molecule that is the mirror image of another molecule. The two mirror-image molecules have the same chemical properties;...
air bearing
A support device in which a column or chamber of air permits the free travel of a mobile part. In optical mounting and...
aspheric
Not spherical; an optical element having one or more surfaces that are not spherical. The spherical surface of a lens may be...
focusing scale
A scale on an optical instrument that indicates the condition of focus. May indicate the distance to the object or diopter...
blocking tool
An instrument used to support optical parts to be cemented, or to be mounted in plaster.
fiber optic cleaver
A device used to prepare optical fiber end faces; a scribe line made by the cleaver's blade propagates across the fiber,...
axis
A straight line, real or imaginary, passing through a body and indicating its center; a line so positioned that various...
Michelson-Morley experiment
An optical experiment carried out conclusively in 1887 that demonstrated that the ether, a hypothetical medium postulated by...
thin-film coating
Thin-film coatings are layers of material applied to the surface of an object or substrate, typically to modify its optical,...
equilibrium length
The length of optical waveguide needed to attain equilibrium mode distribution for a specified excitation condition.
bend radius
The radius of curvature that an optical fiber can bend without breaking.
optical collimator
 fiber optic spectrometer
A fiber optic spectrometer is a device used for measuring the spectral content of light. It utilizes optical fibers to...
field of view
The field of view (FOV) refers to the extent of the observable world or the visible area that can be seen at any given...
wave plate
An optical element having two principal axes, slow and fast, that resolve an incident polarized beam into two mutually...
lateral load test
A method of measuring microbending losses in optical fiber by sandwiching a length of fiber between two parallel plates,...
microdensitometry
The science that deals with the measurement of optical absorbance (i.e. optical densities) over microscopic areas of a given...
optical caliper
A device for measuring linear dimensions. The optical caliper generally consists of two circularly mounted mirrors whose...
chirping
A rapid change, as opposed to a long-term drift, of the emission wavelength of an optical source. Chirping is most often...
long-pass filter
A long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or...
optical tape recorder
An instrument used for video or computer data storage in which a laser optical head is used to write digital information...
solid optics
Optical elements arranged with no spaces between, so that the light travels only through glass, not air.
radiation trapping
That process by which radiation spontaneously emitted by a volume of optical materials is resonantly reabsorbed within the...
optical memory
1. The direct storage of data as bits in memory using optical systems and properties. The memory makes use of a laser beam...
absorption lens
An optical lens manufactured to control the transmission of light over a specified wavelength range. Low absorption lenses...
principal axis
A straight line connecting the curvature centers of the refracting lens surfaces. In a mechanical sense, a line joining the...
photoplethysmography
Photoplethysmography (PPG) is a non-invasive optical technique used to detect changes in blood volume in tissues. It...
photomask
A photomask, also known simply as a mask or reticle, is a key component in the photolithography process used in...
repeatability
The degree to which a predetermined or previous setting of a positioning device can be duplicated by observance of the...
silicon photodiode
A silicon photodiode is a semiconductor device that converts light into an electrical current. It is a type of photodetector...
residual blue
The optical phenomenon in which white light dispersed by small particles in suspension appears blue when viewed through a...
vapor degreasing
A method of cleaning and drying coated optical components. The cooled parts are placed in a container above a boiling...
pyrolysis
A process that employs heat to remove polyimide plastic coatings from silica optical fibers and capillary tubing.
ophthalmology
Ophthalmology is a branch of medicine that focuses on the anatomy, physiology, and diseases of the eyes and visual system....
amorphous
The disordered, glassy solid state of a substance, as distinguished from the highly ordered crystalline solid state....
laser optics
Laser optics refers to a broad category of optical components and systems designed for manipulating and controlling laser...
nanostructured glass
A unique glass made up of nano-structured materials to create millimeter sized monolithic glass space-variant polarization...
conservation of radiance
The principle that states that optical instrumentation cannot increase the radiance of a source; the radiance of an image...
tight buffer
Protective material surrounding the cladding of an optical fiber that allows the fiber no play within it.
transverse interferometry
The method used to measure the index profile of an optical fiber by placing it in an interferometer and illuminating the...
output spectrum display
The direct computation of the Fourier transform of the space variant system output of an optical processor with a single...
proof stressing
A means of testing the strength of optical fibers to ensure reliability, by applying stress to the fiber so that any flaws...
rare-earth type glass
Optical glasses containing the oxides of rare earths such as lanthanum to impart a very high refractive index combined with...
motion controller
In optics, a motion controller refers to a device or system that precisely controls the movement of optical components, such...
aperture diaphragm
The second adjustable iris diaphragm in an optical system. In the common microscope condenser system, it usually is located...
frequency comb
A frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with...
optical theorem
A fundamental law of wave scattering theory that connects the extinction cross section of a scatterer to the real part of...
Brillouin scattering
Brillouin scattering is a phenomenon in physics where an incident electromagnetic wave (usually light) interacts with...
ultraviolet microscopy
The study and photographing of microscope specimens in ultraviolet light; using an optical microscope containing fluorite...
camera tube
The electron beam tube of a television camera that converts an optical image into a pattern of electrostatic charges and...
dispersion
Dispersion refers to the phenomenon where different wavelengths (colors) of light travel at different speeds when passing...
color center laser
Certain color centers in the alkali halides have been optically pumped to produce efficient tunable pulsed and...
nitrogen vacancy
A nitrogen vacancy (NV) refers to a specific type of defect or impurity in a crystal lattice where a nitrogen atom replaces...
reactive evaporation
Reactive evaporation refers to a process in thin-film deposition where a material is deposited onto a substrate through...
microchannel spatial light modulator
A device to modulate spatially a collimated coherent beam of light with input data in optical data processing. It uses a...
ringlight
A circular lamp or bundles of optical fibers placed around the perimeter of an objective lens to illuminate the object field...
optical parametric oscillator
A laser-pumped crystal with nonlinear optical properties inside of an optical resonator in which the output generates...
grinding
The process in the manufacture of an optical system that gives it the required geometric shape.
Kell factor
In an interlaced scanning electro-optical system such as television, the system resolution will be less than the number of...
astigmatic difference
In an optical system having astigmatism, the distance between the tangential and sagittal image planes.
multiple wavelength interferometry
A specific form of phase shifting interferometry - commonly referred to as multiple wavelength phase shifting interferometry...
rare-earth elements
Rare-earth elements (REEs) are a group of seventeen chemical elements found in the Earth's crust, characterized by their...
dielectric lens
A lens made up of a dielectric material that is capable of influencing radio waves much in the same way an optical lens...
optical waveguide preform
 quantum well
A quantum well is a structure in quantum mechanics that confines particles, such as electrons or holes, in one spatial...
bismuth silicon oxide
A photorefractive material used in image processing, holography and optical switching.
Dammann grating
A Dammann grating is a type of diffractive optical element (DOE) used to create an array of equally spaced,...
antifog coating
A coating that is capable of stopping the condensation of moisture on an optical surface.
bright-field image
An optical image having a brightly lit background.
Raman fiber probe
A flexible fiber cable with a small diameter that transports light from the excitation laser to the target. Used in Raman...
nonlinear optical materials
Nonlinear optical materials are substances that exhibit optical properties that are not linearly proportional to the...
fiber bundle
A rigid or flexible, concentrated assembly of glass or plastic fibers used to transmit optical images or light. See aligned...
footprint
1. The sector of the Earth's surface registered upon a remote sensing device in a satellite. 2. The amount of space occupied...
clipping
A defect in an optical system that prevents rays from reaching their intended destination; it can be caused by an undersized...
Abbe prism
A form of roof prism used to invert an image. The prism has faces cut normal to the optical axis; therefore, the prism may...
spiral
A defect in the cleaved end face of an optical fiber in which the surface changes abruptly.
glass laser
An optically pumped solid-state laser in which the active medium is a neodymium ion in a glass rod host. Abbreviated...
ghost
1. A faint second image caused by reflection that is sometimes seen when observing through an optical instrument. 2. With...
rotating wedge
A circular optical wedge (prism of small refracting angle) mounted to be rotated in the path of light rays to divert the...
environmental range
The maximum to minimum range of temperature, pressure, humidity, vibration and biological conditions under which an optical...
near-field scanning
A measurement technique used to determine the spatial distribution profile of an electrical or optical quantity of interest...
optical materials
Optical materials refer to substances or compounds specifically chosen for their optical properties and used in the...
mass relieving
The removal of material from an optical system to decrease the weight and sometimes the bulk of the system. See coring;...
tap
A device for extracting a portion of the optical signal from a fiber.
linear optics
Linear optics refers to the study and manipulation of light in a linear and deterministic manner, where the response of...
optical tooling target
Sets of paired lines carefully designed to give the most accurate pointing possible for various lengths of sight.
optical pumping
The process whereby the number of atoms or atomic systems in a set of energy levels is changed by the absorption of light...
metallographic polishing machine
A small optical polishing machine intended for polishing the surface of a metal specimen before etching for examination...
object space
In an optical system, the space between the object being viewed and the system entrance pupil.
optical density
A measure of the transmittance through an optical medium. Optical density equals the log to the base 10 of the reciprocal of...
optical data storage
The storage of information via optical means, primarily employing a low-power laser to inscribe data on a photosensitive...
radio-frequency discharge laser
A gas laser in which the electrodes are mounted perpendicular to the optical resonator.
optical design and engineering services
Optical design and engineering services involve the development, customization, and optimization of optical systems and...
angular subtense
The measured planar or solid angle of related aspects of an optical system with respect to an optical axis.
metasurfaces
Metasurfaces are two-dimensional arrays of subwavelength-scale artificial structures, often referred to as meta-atoms or...
high-loss fiber
Optical fiber in which the attenuation exceeds the normally acceptable level for long-haul or data communications use.
optical bottle
A term referring to an optical force field used to trap and stabilize particles acted upon by a force such as laser light.
Rayleigh scattering
Rayleigh scattering is a phenomenon that occurs when light waves interact with particles or molecules that are much smaller...
front-cell focusing
A method of focusing an optical system by moving the front component (the lens closest to the subject) to change the...
anamorphic system
An optical system with different focal lengths or magnification levels in perpendicular planes to the optical axis.
lens element
One optical element of a multielement lens. See optical element.
axial bundle
A bundle of rays that originates from an object point on the optical axis of a lens system.
CMOS quantitative polymerase chain reaction system
This type of miniaturized system, referred to as CMOS qPCR, combines microfluidic technology with an ultralow-light CMOS...
distal end
The end of an optical fiber farthest from the source of illumination.
optoelectronics
Optoelectronics is a branch of electronics that focuses on the study and application of devices and systems that use light...
oblique illumination
A common technique in microscopy, oblique illumination is one in which the object is illuminated by a light source that is...
plastic optics
Plastic optics refers to optical components or systems that are made from transparent plastic materials, as opposed to...
magnification
The ratio of the size of the image of an object to that of the object. The ratio of the linear size of the image to that of...
active region
The layer of material in a laser diode from which the optical radiation is emitted; light producing region
magneto-optic readout device
A device using the Kerr effect to read back the signals from mechanically recorded tapes and discs. It consists of a light...
optical tooling level
A surveying device used to measure vertical displacement of target centers of scale lines from a horizontal plane generated...
cyanocrylate cement
Adhering material used to glue optical components that transmit in the infrared. It is easily dissolved by acetone.
optically compensating zoom system
A variable focal length lens system that retains the object in focus as one or more lenses move as a unit along its optical...
polisher pressing
The process of forming a polisher by pressing it with an optical surface.
optical coupling
extrinsic fiber loss
A type of optical fiber loss resulting from the misalignment of fibers in a splice or connector.
sputtering target
A sputtering target is a solid material used in the process of physical vapor deposition (PVD), specifically sputtering....
superresolution
Superresolution refers to the enhancement or improvement of the spatial resolution beyond the conventional limits imposed by...
shading
1. The sorting of lenses by their color. 2. In an optical system, an irradiance or brightness gradient in the image that is...
object
The figure seen through or imaged by an optical system. It may contain structures, natural or artificial, or it may be the...
paraffin oil
A saturated compound of carbon and hydrogen used as a liquid coating material for optical components in high-power laser...
pumping radiation
Radiation used to excite an optical or laser material to a higher energy level. See optical pumping.
eye tracker
An optical device used to monitor movement of the human eye.
fiducial point
One or more spots placed in the field of view of an optical system to provide a means of reference.
optical transfer function
The function that characterizes the quality of an optical system by denoting the modulation and spatial phase shift of the...
liquid crystal
Liquid crystals are a state of matter that exhibits properties intermediate between those of conventional liquids and solid...
blink comparator
An optical system that rapidly alternates two similar pictures or scenes to permit the detection of small dissimilarities...
interference microscope
A special form of microscope that utilizes interference for observing and measuring the phase and optical thickness in...
photonic integrated circuit
A photonic integrated circuit (PIC) is a compact and integrated device that incorporates multiple photonic components and...
polarization-insensitive operation
Capability requirement for optical switches for transmission lines to process arbitrarily polarized light because of the...
gallium arsenide phosphide
Gallium arsenide phosphide (GaAsP) is a semiconductor alloy composed of gallium (Ga), arsenic (As), and phosphorus (P). It...
circular variable filter
An optical interference coating, vacuum-deposited on a circular substrate, whose transmission characteristics may be varied...
magneto-optical photonic crystal
A photonic crystal that comprises magneto-optical material such that the optical response of the device depends on the...
intensity interferometer
An interferometer that functions by first detecting the light striking each aperture and then combining the two detector...
optically pumped laser
A laser in which stimulated emission is triggered by the absorption by electrons of light from an auxiliary source such as a...
averted vision
In astronomy, the method of deliberately viewing objects with peripheral vision to take advantage of the eye's greater...
freeform mirrors
Freeform mirrors refer to reflective optical components that deviate from traditional symmetric or rotationally symmetric...
joint transform correlator
A device consisting of two optical systems in which two signals are simultaneously transformed to produce their spectra, and...
polariscope
A combination of a polarizer and an analyzer that is used to detect birefringence or rotation of the plane of polarization...
periscope
An optical instrument designed to displace the line of sight in a vertical direction. For submarines and other military uses...
electrostatic printer
An instrument used to print an optical image on a specially treated paper. Light and dark portions of the original image are...
vertex
The point of intersection of the optical axis with any centered optical surface.
zip-cord
A two-fiber optical cable containing two single-fiber cables that are connected by a strip of jacket and that can easily be...
marhic method
Nondestructive measurement of the delta and alpha of clad optical fibers that involves interferometry with the fiber...
diopter
A unit of optical measurement that expresses the refractive power of a lens or prism. In a lens or lens system, it is the...
metropolitan area network
A cable backbone used to interconnect local area networks at various sites (corporate offices and factories, for example) in...
whispering gallery mode
Whispering gallery mode (WGM) refers to a phenomenon in wave physics, particularly in optics, where waves, such as light or...
optical beam steering
Directing an optical beam in varying directions by varying reflection, refraction, focusing and diffraction methods.
blocking shaper
A convex, concave or flat cast iron form that is used to shape a soft mold block of optical components.
threshold
1. In visual perception, the minimum value of stimulus that can be perceived on the average. 2. In optical detection...
optical ceramics
Transparent glassy and or crystalline structured materials engineered from inorganic, non-metallic materials via various...
color center
A color center, in the context of materials science and condensed matter physics, refers to a specific type of...
skew ray
Any ray through an optical system that is not a meridional ray. The plane created by a refracted skew ray does not contain...
jig transit
An optical instrument containing a gimballed sighting telescope, used to measure angular relationships in horizontal and...
calibrated wedge
An optical wedge in which transmittance or density is a function of the location of the wedge, relative to a specific...
Schlieren optics
An optical system that records inhomogeneities within a medium by detecting the energy refracted by that portion of the...
field stop
An aperture located at an image plane of an optical system that determines the size and shape of the image.
cladding mode stripper
A mechanism or device, especially a coating with a refractive index equal to or slightly greater than that of an optical...
monolithic lenslet module
An array of refractive microlenses that are round, square and hexagonal and as small as 15 µm. They are used for...
diascope
1. An optical device used for projection of enlarged images of transparencies or lantern slides on a screen. 2. A device...
nonlinear optical phase conjugation
The coupling of laser or light beams via nonlinear optical techniques such as four-wave mixing to achieve spatial variation...
thermal lensing
Distortion of an optical component as a result of heat, which can influence the divergence and the mode quality of a beam...
field of collimator
An expression of the tolerance of decentration of a laser diode from the optical axis: the region around the axis in the...
optical surface
A reflecting or refracting surface contained within an optical system.
terminated crossbar
An optical matrix that does not require perfection in both states of the crosspoint, so that all the optical switches can be...
infrared signal generator
A device that combines electronic and optical techniques to form a monitored infrared signal between 1 and 14 µm. It...
optical transition
The process by which an atomic system changes from one energy level to another by either the emission or absorption of...
metalens
A metalens, short for "metasurface lens," is a type of optical lens that uses nanostructured materials to manipulate light...
marcuse loss theory
A theoretical analysis of radiation loss from planar optical waveguides due to scattering by surface irregularities/surface...
optical pyrometry
The determination of the temperature of a source by the detection of its incandescent brightness.
indium phosphide
Indium phosphide (InP) is a compound semiconductor material composed of indium (In) and phosphorus (P). It belongs to the...
liquid gate
An immersion liquid used to treat polarizing filters to eliminate the effects of surface variations and to minimize the...
variable-speed scanning
A scanning technique in which the optical density of the film being scanned controls the speed of deflection of the scanning...
electron-beam recording
The recording of the information contained in a modulated electron beam onto photographic or silicon resin-coated materials....
Lummer-Brodhun cube
A photometric instrument having two prisms clamped in optical contact to produce a photometric field with an acute dividing...
mounting cement
An adhesive used to hold optical components in their mounts. It may be a thermoplastic or chemical-hardening substance.
optical tweezers
Optical tweezers refer to a scientific instrument that uses the pressure of laser light to trap and manipulate microscopic...
window
1. A piece of glass with plane parallel surfaces used to admit light into an optical system and to exclude dirt and...
glass-melting furnace
A furnace used to heat glass materials. It may be a small laboratory-type furnace for small-scale experiments or large...
Smith-Baker microscope
A transmission interference microscope that produces interference patterns of a sample by using birefringent plates that...
acoustophotorefractive effect
The change in refractive index that occurs as acoustic vibrations are transmitted through an optical material.The index...
xenon flashtube
A high-intensity source of incoherent white light in which a capacitor is discharged through a tube of xenon gas; often used...
decision-tree classification
A structural method of optical character recognition, used where the input media are variable, as in hand-written or...
component
1. A constituent part. It may consist of two or more parts cemented together, or with near and approximately matching...
diffraction grating
A diffraction grating is an optical component consisting of a surface with a periodic structure of equally spaced, parallel...
liquid crystal light valve
A liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the...
supercontinuum
Supercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the...
optical table
An optical table, also known as an optical bench or an optical breadboard, is a specialized platform used in optics...
image contrast
Also referred to as image visibility, the contrast of an image is the variation in the intensity of an image formed by an...
apochromat
An apochromat, often referred to as an apochromatic lens or apochromatic objective, is a type of optical system designed to...
honeycomb table
An optical test table made up of two outer layers or "skins'' bonded to either side of a honeycomblike core, usually of...
simultaneous exposure and development
The process, used with a positive photoresist, in which the photoresist is immersed in developing chemicals while being...
ring blocking
The formation of a block by attaching optical elements to a plate with a ring of pitch or other thermoplastic material.
drive
The hardware for reading (and writing in devices so equipped) an optical mass data storage disk.
hydroxyl ion absorption
An optical fiber's absorption of electromagnetic waves due to hydroxyl ions remaining after contact with water.
multimode distortion
In an optical waveguide,- typically a multimode fiber - the distortion resulting from differential mode delay, i.e. axial...
diamondlike carbon film
A very hard, highly transparent coating based on forms of carbon, used to protect optical components from abrasion and...
compound shutter
A center-opening shutter made up of several identical leaves that are mounted symmetrically around the optical axis of the...
penta prism
A five-sided prism containing two reflecting surfaces at 45° to each other, and two refracting faces perpendicular to...
optical null method
 retina camera
A special-purpose camera used by ophthalmologists to photograph the retina of the eye. The optical system operates through...
barcode scanner
An optical scanning device designed to read information printed in the form of bars of different size by detection and...
optical distance
The physical length of the light path in a substance divided by the refractive index of that substance. See also equivalent...
double vision
A defect of a binocular instrument causing two images to be seen separately instead of being fused. It is caused when the...
anamorphosis
A state in which an image is distorted by an optical system.
field tilt
The angle measured between the focal surface containing the image and a plane normal to the optical axis.
optical lattice
A periodic structure formed by intersecting or superimposed laser beams. These beams can trap atoms in low-potential...
fiber curl
A property of optical fiber that results from thermal stresses during manufacturing and is defined as the amount of...
optical power spectrum
Also known as the Wiener spectrum or the noise power spectrum, the optical power spectrum is a fundamental quantity in...
projecting core coupler
A device that couples a light source to an optical fiber by projecting an image of the source and the fiber core onto a...
optical coupler
cross wire
Fine lines, wires or threads used in the focal plane of many optical instruments to point out and locate particular objects...
optical switching
Optical switching refers to the process of controlling the routing or transmission of optical signals within a network using...
lens blank
A lens blank is a piece of optical material in a raw, unfinished state, typically in the form of a disk or block, from which...
global optimization
A controlled random search process, such as generalized simulated annealing, that has been incorporated into many optical...
surface
1. In optics, one of the exterior faces of an optical element. 2. The process of grinding or generating the face of an...
digital camera
A digital camera is a device that captures and records still images or video in digital format. Unlike traditional film...
beam profiling
Beam profiling is a technique used to characterize and analyze the spatial intensity distribution of a laser beam. It...
multi-axis alignment
Multi-axis alignment refers to the process of aligning or adjusting components or systems in multiple spatial dimensions or...
fiber-coupled LED
A fiber-coupled LED (light-emitting diode) refers to an LED device that is optically coupled to an optical fiber for the...
rhomboid prism
A reflecting prism that is rhomboidal in shape. It has two parallel transmitting faces, and two parallel reflecting faces;...
differential mode attenuation
The variation in attenuation among the propagating modes of an optical fiber.
distributed feedback laser
A distributed feedback laser (DFB laser) is a type of semiconductor laser diode designed to emit coherent, narrow-bandwidth...
adhesion
The intermolecular attraction between two surfaces, as between a substrate and a coating; it is an important factor in the...
optical filter
An optical filter is a device that selectively transmits or blocks specific wavelengths, or colors, of light. Optical...
photodiode
A two-electrode, radiation-sensitive junction formed in a semiconductor material in which the reverse current varies with...
astronomical mirror
An astronomical mirror, also known as a telescope mirror or primary mirror, is a key component of a reflecting telescope. It...
optical multichannel analyzer
 optical correlation
The procedure by which the similarity of an optical signal or waveform to a reference-stored signal or waveform is...
Shack-Hartmann wavefront sensor
The Shack-Hartmann wavefront sensor is an optical device used for measuring the wavefront aberrations of an optical system....
multiple invariance
Characteristic of optical correlators in which invariance to more than one distortion parameter per axis of the processor is...
rare-earth doped fiber
An optical fiber in which ions of a rare-earth element, such as neodymium, erbium or holmium, have been incorporated into...
spread function
The distribution of energy about the image of a point source in the focal plane of an optical system.
apparent luminance
The perceived brightness of an object being viewed at some distance, especially through an optical instrument.
optical interconnection
The use of photonic devices rather than electronic devices to make connections within and between integrated circuits.
offset prism
A prism or prism assembly that serves to displace the instrument's optical axis.
scatterometer
An instrument used to determine the absolute or relative scatter levels of optical surfaces.
blocking pitch
An adhesive used to affix optical elements to an approximately shaped body -- usually of cast iron.
absorbance
The natural log of the ratio of absorbed intensity over the total intensity which gives a constant value assuming a stable...
step index profile
A profile of an optical component, usually a fiber, in which the core is of uniform refractive index and the cladding or...
optical rotation
1. The angular displacement of the plane of polarization of light passing through a medium. 2. The azimuthal displacement of...
optoacoustic
Optoacoustic, or photoacoustic, refers to a phenomenon and related techniques that involve the generation of acoustic waves...
single-mode waveguide (or fiber)
An optical waveguide in which only the lowest order bound mode, which may consist of a pair of orthogonally polarized...
surface wave
A wave that is guided by the interface between two different media or by a refractive index gradient in the medium. The...
gain
Also known as amplification. 1. The increase in a signal that is transmitted from one point to another through an amplifier....
telecentric lens
There are three types of telecentric lenses: -Image-space telecentric lenses are those in which the aperture stop is...
optical delay camera
A type of high-speed cine camera that uses different image paths and a Kerr cell to produce a series of successive images at...
fiber fuse
A phenomenon in which high optical power, encountering an imperfection in an optical fiber, destroys the fiber's core and...
angular spectrum approach
The angular spectrum approach is a mathematical and computational technique used in the field of optics to analyze and...
XYZ axes
Conventional coordinates for optical system analysis, the X-axis being the horizontal, the Y-axis the vertical and the...
stealth
That characteristic which makes a weapon system less visible to radar, optical, acousto-optic, infrared and other military...
circle of confusion
The image of a point source that appears as a circle of finite diameter because of defocusing or the aberrations inherent in...
binary on-off
Signal used in optical transmission systems to generate currents in a detector that are decoded with reference to a...
exit pupil
In a lens or other optical system, the image of the aperture stop as seen from image space.
optical character recognition
Optical character recognition (OCR) is a technology that is used to convert printed or handwritten text into...
electron trapping optical memory
A method of erasable optical data storage in which information is stored by visible light, then read by illumination with an...
minimum object distance
Minimum object distance, often abbreviated as MOD, refers to the closest distance at which a camera lens or optical system...
optical character reader
A photosensitive device used to optically scan and read character data (numbers, letters etc.) and input this data into a...
holography
Holography is a technique used to capture and reconstruct three-dimensional images using the principles of interference and...
mutual coherent function
A function that quantifies the performance degradation of coherent communications systems, imaging systems and all systems...
liquid core optical fiber
Multimode straight fiber capable of transporting linearly polarized light with any incident polarization angle, and in which...
optical resonator
 retroreflection
Retroreflection is a phenomenon in optics where light is reflected back toward its source, typically in a direction nearly...
image quality
A measure of the closeness with which an optical image is capable of resembling the original object. The factors that affect...
Fresnel lens
A Fresnel lens is a type of optical lens that consists of a series of concentric grooves or steps carved into a flat, thin...
phase conjugation
The use of a reflective device, which can be fashioned from a variety of materials including gases, solids, dyes, aerosols,...
optical center
The point on the optical axis of a lens that is the image of the nodal points. For any bundle of rays passing through the...
line source
In the spectral sense, an optical source that emits one or more spectrally narrow lines as opposed to a continuous spectrum....
discontinuously reinforced aluminum
A composite derived from aluminum alloy powder and silicon carbide, used as an optical substrate in air- and spacecraft...
optically biaxial crystal
One of a class of crystalline substances belonging to triclinic, monoclinic and orthorhombic systems that have two optic...
constant linear velocity
Method of disk rotation used for optical disk drives, in which the spindle motor decreases the speed of the disk's rotation...
photoluminescence
The state of optically excited luminescence. Luminescence refers to the light emitted by excited atoms or ions as they decay...
laser
A laser, which stands for "light amplification by stimulated emission of radiation," is a device that produces coherent and...
erect image
An image, real or virtual, whose spatial orientation is identical to that of the object. The image obtained at the retina...
bending of light
1. That action occurring when light passes through an optical interface at other than normal incidence, i.e., refraction. 2....
acceptance angle
The range of angle or solid angle values by which light may enter an optical system.
racemic
Inactive optically, but having the capacity for resolution into forms of opposed optical activity. The term is derived from...
dichroic coating
A dichroic coating, also known as a dichroic filter or dichroic mirror, is an optical coating designed to selectively...
fiber optics
The use of thin flexible glass or plastic fibers as wave guides — or "light pipes" — to channel light from one...
light pipe
Transparent matter that usually is drawn into a cylindrical, pyramidical or conical shape through which light is channeled...
laser velocimeter signal detection
The variation of the electronically detected signal with respect to the scaled version of the classical optical signal...
adhesive
An intermolecular substance that serves to hold materials together. Two types are used in the optical industry: one, which...
coherent fiber bundle
A coherent fiber bundle (CFB), also known as a coherent fiber optic bundle, is an assembly of multiple optical fibers...
isocandela diagram
Indication of emission brightness with degree of emission from an optical source.
write once, read many (WORM)
An optical data storage device that permits the user to store data (write) and play it back (read), but not to erase or...
read-only memory
An optical storage product that can be used for playback only.
optical power
lens testing equipment
Lens testing equipment refers to a range of specialized tools and instruments used to evaluate the optical performance,...
birefringence
Birefringence is an optical property of certain materials that causes them to exhibit different refractive indices for light...
blown fiber
A technique developed by British Telecom in which the viscous drag of air is used to install optical fibers in narrow...
axicon
An optical device that produces a line image lying along the axis from a point source of light; therefore, it has no...
photon jet
A photon jet is a narrow, highly collimated beam of light that is formed when light interacts with small dielectric...
reciprocity law
With respect to photography, the law stating that the optical density of an exposed emulsion with standard development is a...
optoisolator
An optical coupling device that uses light to bridge the gap between incompatible wire communications systems. It contains...
optical lever
A device used to detect and measure small amounts of rotation. The rotating object contains a reflecting surface from which...
read screen
The transparent component of an optical reader that transmits the image rays of the characters to be read.
modified chemical vapor deposition
Modified chemical vapor deposition (MCVD) is a technique used in the fabrication of optical fibers. It is a specialized form...
Senarmont prism
A polarizing beamsplitting prism similar in design to the Rochon prism. However, the Senarmont transmits the extraordinary...
liquid lightguide
An optical fiber with a hollow core filled with a liquid material that has a higher refractive index than the solid...
delay line
A device used to delay transmission of a signal for functions such as memory loops, sequential processing or built-in...
aspherizing
The modification of the spherical surfaces in an optical system to correct for spherical aberration.
photoacoustic imaging
Abbreviated PAI. An imaging modality with a hybrid technique based on the acoustic detection of optical absorption from...
ion-beam sputtering
Ion-beam sputtering (IBS) is a physical vapor deposition (PVD) technique used for depositing thin films onto substrates. It...
optically uniaxial crystal
A transparent crystalline substance in which the refractive index of the optic axis (extraordinary axis) is different from...
rotating hologram
A disc composed of a series of holographic optical elements that diffract light at various angles. When spinning, a raster...
bump-forming optical disk
 radiation mode
A mode in an optical waveguide whose fields are transversely oscillatory everywhere external to the waveguide. It exists...
zoom lens
An optical system of variable focal length, the focal plane remaining in a fixed position. This result is achieved by moving...
integrated photonics
Integrated photonics is a field of study and technology that involves the integration of optical components, such as lasers,...
isolator
In the context of electronics and optics, an isolator refers to a device that allows the transmission of signals in one...
microphotonics
The technology of manipulating light on a micro scale. In optical communications, this is usually accomplished using two or...
optical read-only memory
Generic term for read-only optical data storage, source of the Philips-Sony term CD-ROM.
optical testing
Refers to a variety of methods and tools used to determine the surface contour and performance of optical components and...
read-write capability
In an optical data storage system, denoting the optical head's ability both to record information and to detect it for...
internal surface
A nonoptical surface, within lenses and lens mounts, that contributes largely to flare by reflecting light into the image...
Laurent polarimeter
A Laurent polarimeter is an instrument used in optics for measuring the rotation of plane-polarized light caused by...
fiber optic field flattener
A plate consisting of fused optical fibers with both surfaces ground and polished, and having the entrance surface curved to...
dispersion-limited operation
Operation in which the dispersion of a pulse limits the distance between repeaters in optical systems. Waveguide and...
electron image tube
A cathode-ray tube that increases the brightness or size of an image or forms a visible image from invisible radiation. The...
vignetting
In an optical system, the gradual reduction of image illuminance as the off-axis angle increases, resulting from limitations...
PIN photodiode
A PIN photodiode is a type of photodetector or semiconductor device used to convert light signals into electrical signals....
pigtail
A short length of optical fiber permanently fixed to a component and used to couple power between it and the transmission...
laser fusion
Optical confinement of matter with high field energies intended to induce a stable nuclear fusion interaction.
ray
A geometric representation of a light path through an optical device; a line normal to the wavefront indicating the...
azimuthal polarization
Azimuthal polarization refers to a specific polarization state of light where the electric field vector of the...
read-write head
That part of a magnetic or optical tape or disc drive that retrieves data from or records data on the recording media.
constrigence
Reciprocal of the dispersive power of an optical material. See Abbe constant.
acousto-optics
Discipline within optical physics that addresses sound vibration, phonon effects and their influencing behavior within...
dark current
The current that flows in a photodetector when there is no optical radiation incident on the detector and operating voltages...
sapphire optical fiber
Sapphire optical fiber is a type of optical fiber made from single-crystal sapphire, which is a form of aluminum oxide...
optical cement
A permanent, transparent, and highly transmissive adhesive capable of withstanding extreme temperatures that is applied to...
machine vision system
A machine vision system is an integrated combination of hardware and software components designed to capture, process, and...
material dispersion
The dispersion attributable to the wavelength dependence of the refractive index of the material used in any optical...
meso form
A form of an element that cannot demonstrate optical activity as a result of dextrogyrate and levogyrate effects that are...
annealing
The process of heating and slowly cooling a solid material, like glass or metal, to stabilize its thermal, electrical or...
reflection grating
A reflection grating is an optical component that consists of a series of closely spaced, parallel reflecting surfaces or...
rotational power stability
Ability of a laser to resist variations in output power caused when it is slowly rotated about its optical or symmetrical...
contact blocking
Also called color blocking. The formation of a block by making optical contact between a number of optical elements and a...
graphene
Graphene is a two-dimensional allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal...
spectral domain optical coherence tomography
Spectral domain optical coherence tomography is an imaging technique used in medical diagnostics, particularly in...
prelasing
When uncontrolled laser energy leaks from a laser cavity prematurely, it causes serious damage to optical components and...
scattered fringe period
Measure of the interference fringe pattern produced by the forward scattering of light by an optical fiber; the fringe...
microwave mapping
The pattern of microwave field intensity that can be obtained by detecting the minute expansion of a microwave absorber slab...
optical time-domain reflectometer
An optical time-domain reflectometer (OTDR) is a specialized instrument used in optical fiber communications to characterize...
polystyrene
A plastic used in molded optical components. Styrene elements can be combined with acrylic elements to produce achromatic...
linear plastic
A term for thermoplastic optical materials; that is, those in which the polymer chains remain linear after heating and...
resolution target
A chart on paper or glass containing a series of sets of lines at progressively smaller spacing and used to ascertain the...
Murty interferometer
A form of shearing interferometer that contains a simple wedged (plane-parallel) glass plate with a nonzero optical path...
fiber optic transceiver
A fiber optic transceiver, often simply referred to as an "optical transceiver," is a device used in fiber optic...
double-clad fiber
Double-clad fiber (DCF) is a specialized optical fiber that features two concentric cladding layers surrounding a core. The...
light-beating spectroscopy
The spectroscopic analysis of optical line shapes and frequency shifts, using the technique of light beating; i.e., the...
parametric amplification
Means of amplifying optical waves whereby an intense coherent pump wave is made to interact with a nonlinear optical crystal...
modulation transfer function analysis/measurement equipment
MTF analysis/measurement equipment refers to instruments and tools used to measure and analyze the modulation transfer...
divided slit scan
A scanning technique in optical character recognition in which an array of photocells is used to scan each character to...
registration shift
A shift in the apparent position of an object when an optical element is added or removed.
surface error
The departure of an optical surface from its required tolerance or figure.
acoustical holography
The optical reconstruction of image information contained in a sound field. First the diffraction pattern, formed by an...
large-core fiber
Optical fiber with a large core, often a step-index fiber; "large'' is at times defined as greater than 85 µm.
anamorphote lens
A lens that distorts an optical image.
equilibrium mode distribution
The condition in a multimode optical waveguide in which the relative power distribution among the propagating modes is...
photopumping
The use of light to initiate the lasing process. See optical pumping.
infrared lens
An infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating...
spherical aberration
Spherical aberration is an optical aberration that occurs when light rays passing through a lens or curved optical surface...
fiber optic cable assembly
A fiber optic cable assembly refers to a complete unit consisting of optical fibers, connectors, protective jackets, and...
electro-optic deflection
The effect whereby a light beam is deflected by a birefringent prism when its polarization is changed by voltage applied to...
blue diode laser
A blue diode laser is a type of semiconductor laser that emits light in the blue wavelength range of the electromagnetic...
sensor
1. A generic term for detector. 2. A complete optical/mechanical/electronic system that contains some form of radiation...
stabilizing platform
A platform mount used to hold sensitive optical instruments immobile.
abrasive
Powder used to produce a smooth optical surface through abrasive polishing. Compounds may produce a surface finish specified...
cavity
In a laser, the optical resonator formed by two coaxial mirrors, one totally and one partially reflective, positioned so...
guided mode
In an optical waveguide, a mode whose field decays monotonically in the transverse direction everywhere external to the core...
waveguide dispersion
For each mode in an optical waveguide, the term used to describe the process by which an electromagnetic signal is distorted...
invar
A material often used in the construction of optical instruments because of its low coefficient of thermal expansion (0.9 x...
coherent optical adaptive technique
The use of phase conjugation or other methods to increase the power density of a laser beam under adverse atmospheric...
optical waveguide termination
A configuration or device mounted at the end of a fiber or cable that is intended to prevent reflection.
computer-calculated diffraction pattern
The use of computer analysis in the calculation of diffraction patterns for information on the design of optical systems. In...
microheterogeneous systems
Extremely small organic and inorganic systems of molecules within a substance. In general, systems are colloidal size in...
virtual image
An image that is formed when rays emerging from an optical system are diverging from the optical axis. The virtual image is...
ground state
Also known as ground level. The lowest energy level of an atom or atomic system. A material in the ground state is not...
parcentered
Description of an optical system in which all the elements are aligned on the same axis.
single molecule localization microscopy
Single molecule localization microscopy (SMLM) is a group of super-resolution microscopy techniques that surpass the...
beauty defect
A defect on or in an optical element that does not appreciably impair the function of the surface.
Pockels cell
A Pockels cell, also known as an electro-optic modulator, is an optical device used to control the polarization of light by...
fluoride glass
Optical glass containing zirconium fluoride that results in special characteristics such as improved transmission.
Lorentz oscillator model
The Lorentz oscillator model is a theoretical model used in physics to describe the response of a charged particle (such as...
synchronous optical network
A standard for fiber optic telecommunications interfaces, with a 1300-nm data link operating over single-mode fiber at data...
time-sharing laser
A laser fitted with up to eight optical fibers that transmit the energy to different workstations in turn.
center thickness
The lens thickness measured at the optical axis.
mode hopping
Mode hopping in the context of lasers refers to a phenomenon where a laser system abruptly switches from one longitudinal...
scanning probe microscope
See atomic force microscope; magnetic force microscope; near-field scanning optical microscope; scanning tunneling...
eye relief
Also termed eye distance. The distance between the vertex of the last optical surface of a visual optical system and the...
mirror mount
A mirror mount is a mechanical device used to secure and precisely position mirrors in optical systems. Mirrors are...
compound lens
A lens composed of two or more separate elements of optical glass that may or may not be cemented together. The surfaces of...
power flow equation
Optical fiber channel characterization scheme based on three assumptions; the discrete mode spectrum can be replaced by a...
detector noise-limited operation
In optical communication systems, operations in which the amplitude of the pulses, as opposed to their width, determines the...
nematic phase
A form of liquid crystal with an appearance of moving, threadlike structures, particularly visible when observed in thick...
dynamic fatigue
Stress applied to an optical fiber at a constant rate.
fiber optic cable
A package for an optical fiber or fibers that may include cladding, buffering, strength members and an outer jacket.
actinic focus
That point in the electromagnetic spectrum at which an optical system focuses the most chemically effective rays.
head-up display
An optical system that superimposes a synthetic display providing navigational or weapon-aiming information on a pilot's or...
aerial reconnaissance
The use of optical or electronic recording systems to extract information from the terrain, while aloft, for reconnaissance...
macrobending
In optical fiber, bends that are larger than microbends (see microbending), being visible. Generally they are caused by...
cinesextant
An optical instrument used to track and image a test vehicle (target) throughout its flight. The cinesextant frequently...
preform
A glass structure from which an optical fiber waveguide may be drawn.
solar simulator
A solar simulator is a device used to replicate the spectrum and intensity of sunlight in a controlled environment for...
Risley prism
A Risley prism, also known as a Risley prism pair or Risley rotating prism, is an optical device used for controlling the...
dark noise
The noise produced in a photodetector when the photocathode is shielded from all external optical radiation and operating...
aspheric lens system
An optical system having one or more lens or mirror components that have nonspherical surfaces. These surfaces, whether...
photocoagulator
An optical medical instrument that uses an intense, precisely focused beam of light to stop weakened blood vessels from...
diamond-turned optic
Diamond turning refers to a precision machining process used to produce complex optical components, particularly lenses and...
fiber optic sensor
A fiber optic sensor is a device that uses optical fibers to detect and measure physical, chemical, biological, or...
analyzer
An optical device, such as a Nicol prism, capable of producing plane-polarized light, and used for detecting the effect of...
harmonic generation
Harmonic generation refers to a nonlinear optical process in which incoming photons interact with a material and produce new...
replicated optics
Optical components, usually reflectors, produced using proprietary techniques that transfer the precision of a master to a...
gauze technique
The masking of all openings of an optical transform -- except the hole at the symmetrical center -- with a thin wire gauze...
edge response
Intensity distribution in the image of an edge. The gradient of the edge-response curve is a measure of the image quality of...
styrene acrylonitrile
A copolymer of styrene and acrylic used in molded optical components; it has a high refractive index and a low coefficient...
moiré deflectometry
An optical interference technique widely utilized as a method of nondestructive testing when determining the ray deflection...
nonlinear optical processing
Derivative of the half-tone screen process involving the fabrication of a binary pulse-width modulated copy of the...
modulator
A modulator is a device or component that modifies a carrier signal in order to encode information for transmission over a...
lens mount
The metal tube that maintains the optical components of a lens in proper relationship. Some lenses are mounted in metal...
dispersion-flattened single-mode fiber
A type of glass optical fiber that provides low pulse dispersion over a broad portion of the light spectrum and as a result...
lead zirconate titanate
A ferroelectric polycrystalline ceramic material used in optical memories for computers and as a piezoelectric transducer.
infrared scanner
An optical system used to collect infrared energy from a scene using scanning optics with a point or line detector, as...
superfluorescence
The process in which the normal rate of fluorescent emission from a substance is enhanced by virtue of the optical gain of...
dye-polymer optical disc
A type of erasable data storage device that uses a medium deposited on the disc in two layers, each dyed to absorb a...
macrobend loss
In an optical waveguide, that loss attributable to macrobending. Macrobending usually causes little or no radiative loss.
optical resolution
A measure of image quality produced by an optical system. May be specified in terms of cycles per millimeter, referencing a...
plasmon ion-assisted deposition
Plasmon ion-assisted deposition (PIAD) is a technique used in thin-film deposition processes, particularly in the production...
local oscillator laser
In coherent optical communications systems, a laser used at the receiving end to produce a steady wave that is combined with...
peel point
In a fiber optic guided missile, the point at which the optical fiber pays out from the bobbin on which it is wound.
polarizer
An optical device capable of transforming unpolarized or natural light into polarized light, usually by selective...
sapphire window
A sapphire window refers to a transparent optical component made from sapphire crystal. Sapphire is a single-crystal form of...
mode coupling
In an optical waveguide, the exchange of power/energy among modes.
outside vapor-phase oxidation
A process for the production of optical fibers. A glass bait is rotated in a traversing flame of a reaction burner....
fluorite
The optical form of the crystal fluorspar, calcium fluoride, that is utilized for its low optical dispersion, its low...
crown glass
One of the two principal types of optical glass, the other being flint glass. Crown glass is harder than flint glass, and...
residual gas analysis
A measurement in optical thin-film coating processes whereby the gases remaining in the vacuum chamber after coating are...
coupler
1. In color development, the chemical that combines with certain by-products of the development procedure to form a dye. 2....
photonic crystal surface-emitting laser
A photonic crystal surface-emitting laser (PCSEL) refers to a type of laser diode that emits light from its surface rather...
optical clock
An optical clock is a highly precise and advanced timekeeping device that relies on the oscillations of electromagnetic...
polishing
The optical process, following grinding, that puts a highly finished, smooth and apparently amorphous surface on a lens or a...
optical-grade silicon
The element that resembles a lightweight metal, but when very pure, has a very high electrical resistance and is transparent...
terahertz spectrometer
A terahertz spectrometer is a scientific instrument used to measure and analyze the properties of materials in the terahertz...
helmet-mounted display
A compact optical projection system, mounted on or built into a helmet, and used to project data or a scene directly into...
numerical aperture
The sine of the vertex angle of the largest cone of meridional rays that can enter or leave an optical system or element,...
multifiber joint
A fiber optic connector or splice that mates two multifiber cables, optically aligning all of the individual fibers...
massive optics
Optical components exceeding 24 in. in diameter. The components are usually glass, acrylic or polystyrene and are used for...
optical coherence tomography imaging system
Optical coherence tomography (OCT) is an imaging technique used in medical diagnostics and biomedical research to obtain...
ultrasonic cleaning equipment
Ultrasound used in the cleaning of metal and optical parts by virtue of its vibration rates. Large acoustic forces break off...
horizontal travel
The rotation of an instrument (or the line of sight of an optical system) in a horizontal plane; transverse.
amplified spontaneous emission
Broadband radiation emitted by a laser that does not transmit through the optical element. It can be removed by filtering.
micro-optical coherence tomography
Micro-optical coherence tomography (micro-OCT) is an imaging technique that is an adaptation of optical coherence tomography...
spatial light modulator
A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of...
sensitized fluorescence
The optical energy transfer between ions of differing atoms.
near-infrared camera
A near-infrared (NIR) camera is an imaging device designed to capture images in the near-infrared region of the...
light sheet fluorescence microscopy
Also known as single plane illumination microscopy (SPIM), this process was designed for imaging of sensitive samples and...
scoring
The cutting of pitch tooling surfaces by an optical technician to permit polishing compounds to flow across the surface of...
optical communications
The transmission and reception of information by optical devices and sensors.
instantaneous field of view
Instantaneous field of view (iFOV) is a term commonly used in the context of remote sensing, imaging systems, and optical...
automated optical inspection
Automated optical inspection (AOI) is a technology used in manufacturing processes, particularly in electronics, to...
rectilinear system
An optical system that is corrected for distortion and spherical aberration and therefore forms the image of a straight line...
aplanatic points
Aplanatic points refer to specific points in an optical system where certain aberrations, such as spherical aberration or...
overall distance
The physical distance, measured along the optical axis, from the object to the image. Also called overall length.
eccentricity
In the tolerancing of optical elements, the displacement of the optical axis from the mechanical axis.
laser damage threshold
The laser damage threshold refers to the maximum level of laser intensity that a material can withstand without experiencing...
optical fiber optic switches
Optical fiber optic switches are devices used in optical fiber communication systems to selectively route optical signals...
optical path length
In a medium of constant refractive index, the product of the geometrical distance and the refractive index.
viewfinder
A device, optical or electronic, that may be joined to a camera so that the operator may perceive the scene as the camera...
pulse spreading
Variations in a signal passing through an optical fiber caused by the effect on the pulse of the fiber's material and mode...
stripper
A tool used to remove the outer cladding of an optical fiber without damaging the fiber core.
convex
Convex is an adjective used to describe a surface or shape that curves outward, bulges, or has a rounded and outwardly...
null process
Commonly performed in spectroscopy, the optical null process is a method for radiation detection whereby physical detectors...
dynamic spectroscopy
A spectroscopic technique used to display the intensity of an optical pulse as functions of time and frequency...
diffuse modulation transfer function
Modulation transfer function of an optical element when used for transporting images from a lambertian source such as...
astronomical telescope
An astronomical telescope is a type of optical instrument designed to gather and magnify light from distant celestial...
transverse scattering
The method for measuring the index profile of an optical fiber or preform by illuminating it coherently and transversely to...
focal power
In a symmetrical optical system this is a measure of the influence of the system upon the focus of a pencil of rays passing...
orthographic camera
A camera designed with a telecentric optical system and a narrow field of view; the telecentric optical system (placement of...
structured illumination microscopy
Structured illumination microscopy (SIM) is an advanced optical imaging technique used in microscopy to enhance the...
oscillograph
An instrument used to record rapidly varying currents or voltages. An oscillograph may consist of a cathode-ray tube...
optical dynameter
A small low-power microscope or magnifier with a scale that is used to measure the exit pupil diameter and eye relief on...
monochromator
A monochromator is an optical instrument used to isolate and select a narrow range of wavelengths from a broader spectrum of...
structural color
Structural color refers to coloration in materials that is not caused by pigments or dyes but is instead a result of the...
optical molasses
hybrid optical integrated circuit
Device in which the various circuit elements are fabricated in different substrate materials and then appropriately joined...
metal component
An accurate metal prism or plane parallel plate that is cemented to an optical element and remains with it during a series...
deblocking
The removal of optical elements from a block.
half-wave plate
A plate of electro-optical material that serves to rotate the plane of polarization of a light beam.
spheric lens
A spheric lens, also known as a spherical lens, is a type of optical lens with at least one surface that is part of a...
armor
A protective jacket added to an optical fiber to facilitate use in harsh environments. Armor usually consists of steel or...
etalon
An etalon is an optical device that consists of two parallel reflecting surfaces separated by a precise and known distance....
transversely excited atmosphere laser
Also known as TEA laser. A coherent optical source with a wide wavelength range in the infrared, visible and ultraviolet...
second-order nonlinear optical properties
Second-order nonlinear optical properties refer to a class of phenomena exhibited by certain materials in response to...
active layer
That layer in a semiconductor injection laser or light-emitting diode that provides optical gain.
reference surface
The surface of an optical fiber that is used as a reference when joining optical fibers. Although the outermost cladding is...
optical Doppler effect
polarization
Polarization refers to the orientation of oscillations in a transverse wave, such as light waves, radio waves, or other...
molecular modeling
A method of predicting the nonlinear optical effects exhibited by different molecules without synthesizing the molecules...
mandrel
A shaft, spindle or any object generally passed through a workpiece to hold, support or shape a particular piece during its...
Abaxial ray
Ray oriented and assumed to propagate orthogonal to the optical axis
optical fluorography
The fluorographic method whereby the visible image (as opposed to the x-ray image) is photographed by mounting a camera in...
linear positioning stage
A linear positioning stage, also known as a linear stage or translation stage, is a precision mechanical device used to...
layout
In the optical shop, the process of positioning and marking a blank or lens before surfacing, cutting and edging.
laser velocimeter
A system that uses a continuous-wave laser to measure the velocity of an object by focusing the laser beam on the object,...
differential interference contrast microscopy
Differential interference contrast (DIC) microscopy, also known as Nomarski interference contrast microscopy, is an optical...
retina
1. The photosensitive membrane on the inside of the human eye. 2. A scanning mechanism in optical character generation.
boresight
The alignment process that makes the optical axes of two related systems parallel to each other. Also, making the optical...
scratch
A defect on a polished optical surface whose length is many times its width. Block reek is a chainlike scratch formed in...
surface quality standards
The standards of MIL-O-13830 set by the US government relative to tolerable surface scratches and other such defects in an...
circular dichroism spectroscopy
A type of spectroscopy used extensively in the analysis of biological samples. Because most biologically synthesized...
optical phonon resonance
The point at which infrared transmission is cut off.
antireflection coating
An antireflection coating (AR coating) is a thin film or coating applied to optical surfaces, such as lenses or windows, to...
photonic crystals
Photonic crystals are artificial structures or materials designed to manipulate and control the flow of light in a manner...
germanium crystal
Germanium crystal refers to a crystalline form of the element germanium (Ge), which is a metalloid and semiconductor...
mandrel wrap test
A means of testing optical fiber for macrobending losses by wrapping the fiber once at very low tension around a mandrel,...
achromat
An achromat, in the context of optics, refers to a type of lens or lens system designed to reduce chromatic aberration....
electrostatic lens
The electrical distribution that serves to influence an electron beam in the same way that an optical lens affects a light...
stereomicroscopy
The use of a specialized optical microscope designed to provide a more three-dimensional view of a sample. Stereomicroscopy...
aberration sensor (wavefront sensor)
Designed for the function of optical wavefront analysis. Shack-Hartmann camera aberration sensors use a lens array to image...
evaporation coating
Coating carried out in a sealed chamber evacuated by a mechanical pump in series with an oil diffusion pump to a pressure...
diasporometer
In an optical rangefinder, the system of wedges that rotate in opposite directions to aid in the detection of deviation in...
modulator crystal
A nonlinear crystal used to modulate a polarized beam of light by means of the Pockels effect. A Pockels cell is used as a...
optical chopper
A mechanical or electrical-electromagnetic device for periodically interrupting or blocking abeam of light for a brief known...
error function
A single number, defined by the computer program or the user that expresses the performance of an optical system. Also known...
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...
digital optical processing
The scanning of photographs or transparencies of images, either by a vidicon camera or flying spot scanner, for the...
telescope lens
A telescope lens is a primary optical component of a telescope system that gathers and focuses light to form an image. It is...
equivalent air path
When a block of glass (prism, window, filter, etc.) is placed into a converging light bundle, it increases the physical...
optical flat
A piece of glass, pyrex or quartz having one or both surfaces carefully ground and polished plano, generally flat to less...
electro-optic modulator
An electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an...
calcium fluoride
An optical material used in place of crown glass to produce lenses with extraordinary correction of chromatic aberrations....
combiner
A semitransparent mirror in an optical system that combines two or more output beams into a single coaxial beam.
photometric equipment
Photocells of various kinds used to measure photometric quantities; i.e., intensity, luminance and illuminance. Meter...
figure
In optics, the geometrical form of an optical surface.
optical path difference
The relative path difference (or phase shift) traveled between two rays that pass through different mediums from the same...
rangefinder
1. An optical distance finder that depends on triangulation of two convergent beams on an object from disparate view points....
dissector
In optical character recognition, the mechanical or electronic transducer used to detect the level of illumination present...
molded lens
A molded lens is an optical lens manufactured using a molding process, typically involving the shaping of a material, such...
quantitative phase imaging
Quantitative phase imaging (QPI) is an advanced imaging technique used in microscopy to measure and analyze the optical...
diode laser
A diode laser is a type of laser that uses a semiconductor diode as the active medium to generate coherent light....
contact microradiography
The radiography of small objects having detail too fine to be seen by the unaided eye. The resulting negative, when...
gradient-index profile
The term gradient-index profile refers to a specific type of refractive index distribution within an optical material. In...
hollow waveguide
An infrared-transmitting optical fiber with a hollow core; it can be square, round or rectangular in cross section. Capable...
mirror blank
A mirror blank refers to the initial piece of material from which a mirror is made. It is typically a flat or slightly...
optical assembly
An optical assembly refers to a collection of optical components that are carefully arranged and aligned to perform a...
galvo-directing mirrors
A system of mirrors that can be used to direct light from a single laser source into any one of a number of separate optical...
liquid coating
A self-healing, index-matching, nonporous coating for optical components that can eliminate production difficulties and...
etaloning
Etaloning is an optical phenomenon that occurs in imaging systems, particularly in devices such as spectrometers,...
protective coating
A film applied to a coated or uncoated optical surface primarily for protecting this surface from mechanical abrasion, from...
photodiode detector
A photodiode detector is a semiconductor device that converts light into an electrical current. It operates based on the...
multiconfiguration mode
Used in computer design for optical systems with common parts and different applications.
laser line filter
A narrow linewidth optically transmissive or reflective component intended for use with a highly monochromatic or single...
optical relay
 erbium-doped fiber amplifier
An optical fiber that can be used to amplify an optical input. Erbium rare earth ions are added to the fiber core material...
fog
1. A term used to describe the clouded appearance of an incompletely polished surface that scatters light. 2. The...
lateral shearing interferometer
A lateral shearing interferometer is an optical device used in interferometry to measure phase differences between two beams...
ultrasonic light diffraction
The optical diffraction spectra formed, or the method that produces them, when a light beam is transmitted through a...
phase-only filter
A type of matched filter that responds only to the phase of incoming light; the output has a much greater intensity than...
chromascope
An instrument designed to analyze the optical effects of color.
Strehl ratio
The ratio of the illuminance at the peak of the diffraction pattern of an aberrated point image to that at the peak of an...
laser active elements
Laser active elements typically refers to the substances or materials within a laser system that play a critical role in the...
jig allowance
Also called coating jig allowance. That margin on an optical component that is outside the clear aperture for use in holding...
optical encoder
A device designed to measure linear or rotary motion by detection of the movement of markings on a transparent medium past a...
dioptric system
An optical system that uses refraction to form an image.
flint glass
One of the two major types of optical glass, the other being crown glass. Flint glass is softer than crown glass, has a...
catastrophic optical damage
The darkening of the laser facet of a semiconductor laser diode. It can be prevented by placing the component in a...
phase
In optics and photonics, "phase" refers to a property of electromagnetic waves, such as light, that describes the position...
mode scrambler
A device for inducing mode coupling in an optical fiber. Also, a device composed of one or more optical fibers in which...
single-molecule spectroscopy
An advanced technique that allows the detection of one molecule within a crystal or a cell through optical excitation....
optical element
An optical part constructed of a single piece of optical material. It is usually a single lens, prism or mirror.
photonic cavity
A photonic cavity, also known as an optical cavity, is a structure that confines electromagnetic radiation within a certain...
digital holographic microscopy
Digital holographic microscopy (DHM) is an advanced imaging technique that combines holography and digital image processing...
baffle
An opaque shielding device designed to reduce the effect of stray light on an optical system.
fiber optic ribbon
A coherent optical fiber bundle in which the configuration is flat rather than round, giving an output in a line.

(1,275 results found)

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