In coherence theory, an optical law put forth by physicist Emil Wolf that explains the behavior of light as it travels away from its source over large distances in space. Light spectra are assumed to remain uniform as light travels, but may change...

In interlaced television scanning, an effect in which the lines of one field fail to fall exactly within the lines of the...

Conceptual formulas that characterize both the transmittance functions of lenses and propagation in the Fresnel zone.

A group of four cameras loaded with different combinations of filters and film (one is usually an infrared color film) to...

Molecules composed entirely of carbon, in the form of a hollow sphere, ellipsoid or tube. Also called buckyballs....

A departure from ideal paraxial imaging behavior. The distortion of an optical field wavefront as it is propagated through...

An optical waveguide in which only the lowest order bound mode, which may consist of a pair of orthogonally polarized...

A technique for creating optimal performance in a system by producing a specific beam irradiance distribution, usually...

Spectroscopy characterized by the Mossbauer effect - recoilless emission and absorption of nuclear gamma radiation- which...

An instrument used to measure the temperature of a source through the use of photoelectric cells to detect and measure the...

A photodiode having a conducting grid that covers the surface of the photodiode junction and intercepts and wastes some of...

In a lens or other optical system, the image of the aperture stop as seen from image space.

Having human characteristics or behavior.

The concave portion of a surface, formed on a blank, on which the disk of higher refractive glass will be fused to form a...

An instrument for measuring the radius of curvature of a spherical lens or mirror surface. It may consist of a ring resting...

A precisely defined series of steps that describes how a computer performs a task.

Also known as display primaries. Colors formed by a television receiver that are of constant chromaticity and variable...

A laser with output over a wide range of wavelengths spanning the far-infrared region of the spectrum (30 to 1000 µm);...

A shutter consisting of a ring of interweaving blades that open outward and allow light to pass when they are pivoted at...

The process of perforating a silicon or ceramic substrate with a series of tiny holes along which it will break. Nd:YAG or...

1. A contour map of a photographic deposit consisting of lines and curves that join points of equal density. 2. The...

Interferometric measurement of the interference pattern recorded when a complex object is illuminated by two laser pulses...

The application of aerial photographs as a means of measurement in map making and surveying.

In a cathode tube, the electrode that serves as a source for electrons.

Electric polarization characterized by homogeneous polar dielectrics and ascribed to the position of the permanent molecular...

The generic term applied to all sources of visible radiation from burning matter to ionized vapors and lasers, regardless of...

An electron system using the effect of a constant magnetic field on electron paths to differentiate electrons that have...

In photoelectric sensing, the portion of the transmitted beam that actually functions in the system; the diameter of the...

In gradient index optics, a gradient profile in which the refractive index varies along the direction of light propagation,...

A reflecting grating ruled on a concave spherical surface that not only disperses the light but focuses the spectrum. The...

The superposition of satellite or aerial images with a map in order to process and remove distortion. Uses reference points...

Positioning generally refers to the determination or identification of the location or placement of an object, person, or...

A type of erasable data storage device that uses a medium deposited on the disc in two layers, each dyed to absorb a...

A medical technology that uses lasers or other light sources in combination with photosensitizing drugs to treat cancerous...

A prism is a geometric optical element with flat, polished surfaces that refract light. It is typically a solid, transparent...

The point to which the extension of the straight line, reaching from the sun to the observer's eye after penetrating the...

A spectroradiometer having a means to scan different regions of the light spectrum, providing simultaneous representations...

A superconducting bolometer, operating at very low temperatures, that is used to detect infrared radiation.

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...

A single-photon avalanche diode (SPAD) is a specialized type of photodetector designed to detect extremely weak optical...

A camera designed to form a continuous record of an expansive section of the horizon. The typical panoramic camera is...

The series of interference bands that appear in the spectrum when a specified glass plate is inserted into a spectroscope,...

Used in computer design for optical systems with common parts and different applications.

A deliberately nonlinear amplitude modulation that strengthens weak signals and reduces strong signals for transmission.

The masking of all openings of an optical transform -- except the hole at the symmetrical center -- with a thin wire gauze...

Integrated photonics is a field of study and technology that involves the integration of optical components, such as lasers,...

A spectrophotometer having a prism or, more frequently, a grating for the study and recording of infrared spectra. It...

The process of adjusting input pixel by pixel at the filter plane to adapt to nondeal phase behavior in an optical...

Amplification; the result of the excess of stimulated radiation over absorbed radiation.

The current that flows in a photodetector when there is no optical radiation incident on the detector and operating voltages...

A lens having an extremely high aperture and used in the recording of x-ray fluorescent screen images. It often is specially...

Material hardness scale that is used to characterize the scratch resistance of various materials. This surface hardness...

1. In the eye, the opening in the iris that permits light to pass and be focused on the retina. 2. In a lens, the image of...

A high-contrast transparency of the gas sought, or an array of exit slits that correlates with some features of the...

Infrared optics refer to optical components and systems designed to manipulate and control infrared (IR) light, which lies...

A frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with...

Broadband dielectric mirrors, also known as broadband mirrors, are optical coatings designed to efficiently reflect or...

The ray refracted by a sphere of transparent material that travels back as closely as possible to the original path formed...

A coherent fiber optic bundle made from fibers whose diameter changes gradually along its length. Used to magnify or reduce...

The formation of a picture or image in which the density gradients in a volume of flow are rendered visible. The image is...

Location on the CIE chromaticity diagram which produces the color white for a given light source at a specified temperature.

The method by which Thomas Young in 1802 disproved Newton's corpuscular theory of light by the formation of interference...

The lens of an eyepiece nearest the observer's eye.

A piece of glass polished flat on one side, with a pair of polished faces that form an angle close to 180° on the other...

A digital imaging method whereby the first gray level of each sequential point-by-point sample and its position in the...

An optical element having two principal axes, slow and fast, that resolve an incident polarized beam into two mutually...

A type of birefringent polarizing prism that transmits the extraordinary ray and removes the ordinary ray through total...

The number of separate images exposed by a cine camera in a second or the number illuminated by a cine projector in a...

Optical manufacturing tools and machinery encompass a wide range of equipment, instruments, and systems used in the...

A photodetector mounted in the same package as a laser diode that is positioned to monitor the output from the rear facet of...

The process of attaching a device to the end of a fiber cable to enable the beam to be transmitted farther, to pass to...

Describing a laser in which the gas is permanently sealed within the tube.

A positioning slide mechanism with two rows of alternately crisscrossed cylindrical rollers.

Luminous flux emitted by a source in a given range of directions; the unit of measure is the lumen/steradian, now known as...

An instrument that detects high-energy charged particles by analysis of the Cerenkov radiation that they emit.

The scattering of x-rays by the regularly spaced atoms in a crystal. The angle at which the reflection occurs is known as...

In image processing, modifying the dot that forms the image in order to simulate a series of gray tones.

A lens aberration in which the focal length varies radially outward from the center of the field. It has the effect of...

The area of optics in which the propagation of light is described by geometrical lines (or rays) governed by Fermat's...

An analog method of moving a cathode-ray tube beam across a display screen face, commonly used in high-performance vector...

When splitting the output of a single optical fiber into two or more fibers, the difference in the maximum loss between any...

A type of geometrical distortion that brings about a trapezoidal display of a nominally rectangular picture. Usually...

A filtering method that restores a blurred image by setting its power spectrum equal to that of the original image.

A qubit, short for quantum bit, is the fundamental unit of information in quantum computing and quantum information...

The use of photographs to record astronomical objects and phenomena for purposes of physical observation and measurement of...

In data communications, the instrumentation connecting two stations: transmitters, receivers and the cable that runs between...

An organic light-emitting diode (OLED) is a type of light-emitting diode (LED) technology that utilizes organic compounds to...

An analysis used for problems of wave propagation. The principle notes that each point of an advancing wavefront is the...

Noise generated by the random variations in the number and velocity of the electrons from an emitter.

A plate of glass in which a face has been frosted by grinding or etching. It diffuses light by scattering in directions...

A machine vision technique of image correlation whereby the correlation kernel (template of the desired image) is...

Radiance per unit wavelength interval at a given wavelength, expressed in watts per steradian per unit area per wavelength...

The rate of diminution of average optical power and the sum of the scattering and absorption coefficients.

A camera used in scintillation recording to make a visible record of the distribution and relative concentration of...

The recording of the information contained in a modulated electron beam onto photographic or silicon resin-coated materials....

Machine vision, also known as computer vision or computer sight, refers to the technology that enables machines, typically...

A transparent powdered solid immersed in a liquid or plastic of similar refractive index but widely different dispersion;...

The process of forming a polisher by pressing it with an optical surface.

An electro-optical infrared tracker consisting of a beamsplitter, an illuminating source, an image dissector tube and an...

A method of measuring flow velocity by seeding the flow with neutrally buoyant particles and using a pulsed laser to...

Photogrammetric compensation for incidental camera movement (which prevents attainment of true vertical photographs) whereby...

A photodetector, also known as a photosensor or photodiode, is a device that detects and converts light into an electrical...

Technique that uses high-pass filtering to reduce the local average to zero for all regions of the picture and then applies...

Ophthalmology is a branch of medicine that focuses on the anatomy, physiology, and diseases of the eyes and visual system....

A unit of metric measurement, equal to 0.001 m. 25.4 mm equal 1 inch.

The adjustment of the eyepiece of an instrument to provide accommodation for the eyesight differences of individual...

The process of microphotography that involves the reduction of the original at a ratio greater than 100 to 1. The process is...

The degree to which a predetermined or previous setting of a positioning device can be duplicated by observance of the...

A photoconductive cell having cadmium sulfide as its photoconducting material for the production of a very high dark-light...

An electronic flash tube capable of repeated operation at hundreds or thousands of flashes per second for long periods.

A type of matched filter that responds only to the phase of incoming light; the output has a much greater intensity than...

A grating used as a reflectance filter, particularly in the far-infrared. Small plane gratings, blazed for the wavelength of...

The dispersion of a light ray striking the surface of a biaxial crystal, in which the resulting rays are reflected in a...

The logarithmic method of determining emulsion speeds developed by the German standards organization, Deutscher...

An array of spectral lines formed when a beam of electrons, striking a crystalline solid, is scattered. It is used in the...

A digital imaging method whereby the first gray level in the ordered sequence and the position of the first lengths of all...

A study of the energies and wavelengths of radiation emitted by atoms and molecules when particular physical conditions are...

An equation that uses the wavelength of light passing through a medium, along with a set of coefficients, to calculate the...

An infrared source, set in a stationary position, that is used as a reference in certain navigational systems.

In a laser, the optical resonator formed by two coaxial mirrors, one totally and one partially reflective, positioned so...

An advanced technique that allows the detection of one molecule within a crystal or a cell through optical excitation....

A filter that separates light into many colors via Bragg's law. Generally refers to a fiber Bragg grating used in optical...

Also known as a gray body; a nonselective radiator is a thermal radiator that has a constant spectral emissivity with...

Mount attached to a camera or camcorder which allows the user to attach a microphone or flash unit.

Heat loss determined by the sum of rising and falling slopes at a constant temperature.

A form of photography in which an electronic camera converts an image to an electronic signal that is stored in digital...

An image-forming instrument in which a strong electrostatic field causes cold emission of electrons from a sharply rounded...

Pockels cell or dynamic optical retarder in which the electrical field is applied in a direction parallel to that of light...

A photoconductive cell consisting of a layer of selenium on a substrate whose electrical resistance varies with the...

In a multicrystalline material, the meeting point between crystallites.

In an optical fiber or waveguide communications system, an optoelectronic device or module that receives an optical signal,...

One area of image enhancement, accomplished by spatial filtering schemes, that usually involves attenuation of phase changes...

An image-forming system that uses mirrors rather than lenses. Such objectives are frequently used for astronomical...

The allowable departure from the given figure or geometrical form. It may be described in terms of fringes or wavelengths.

The direct cladding used for fused silica cores to create large numerical aperture fibers and used as overcoats to...

The dip or gap in the profile of a laser beam's line width when it is both homogeneously and inhomogeneously broadened. When...

In optical character recognition systems, the identification of a character facilitated by means of known factors governing...

Scanning electron microscopy (SEM) is an advanced imaging technique used in microscopy to obtain high-resolution,...

A device that determines the lens shape in the cutting or edging phase of fabrication. It also is used to denote the...

Time elapsed during the radiant output change from 10 to 90 percent of maximum in a light-emitting diode or laser. Usually...

A biomarker, short for biological marker, refers to a measurable and quantifiable indicator of a biological condition,...

Fluence is a term used in various scientific and technical disciplines to describe the amount of something per unit area....

The study of x-rays, their biological effects and technology. Named for W.C. Roentgen, who discovered x-rays in 1895.

The present radiation level within a laser or electromagnetic radiation operating area.

An area in which airborne particulates can be monitored and controlled so that given size particles do not exceed a...

The condition in which there are more atomic systems in the upper of two energy levels than in the lower, so stimulated...

A portable instrument that uses a four-sided reflecting prism or set of mirrors to create a duplicate image of an object on...

The holographic recording of the pattern formed by two sets of coherent microwaves that interfere at a scanning plane. A...

The method for measuring the index profile of an optical fiber by preparing a thin sample that has its faces perpendicular...

Means of amplifying optical waves whereby an intense coherent pump wave is made to interact with a nonlinear optical crystal...

Thermal interface materials (TIMs) are substances or compounds used to enhance the thermal conductivity between two surfaces...

The term "metaverse" refers to a collective virtual shared space, created by the convergence of virtually enhanced physical...

A high-frequency approach to the propagation of light in graded-index fibers in which the modal field is represented in...

Any object that emits radiation of a wavelength lying between about 0.75 to 1000 µm. A calibrated secondary source...

Optical design software refers to specialized computer programs used by optical engineers, physicists, and designers to...

A finite version of Shannon's sampling theorem that states that a class of functions can be reconstructed exactly by a...

The fiber optic connector standard for Nippon Telephone & Telegraph (NTT) installations, developed with Nippon Electric...

A system used for gratings that consists of a concave mirror, a grating and a plate holder mounted normal to the grating to...

An exaggerated depth appearance in stereo photographs caused by the lenses in the camera being farther apart than the eyes...

An excited energy state of an atom or atomic system that has a longer lifetime than the ordinary excited state and typically...

Irregular waves; e.g., light waves, having little coherence and a broad spectrum of frequencies.

A device having electrical resistance and used in an electric current for purposes of protection, operation or control of...

A small optical polishing machine intended for polishing the surface of a metal specimen before etching for examination...

A telescope that is fixed or has a limited degree of movement in a vertical plane; primarily used to determine the position...

A cable assembly containing both optical fibers and copper electrical conductors in the same jacket.

A uniaxial, birefringent crystal having an ordinary ray with a higher velocity than the extraordinary ray.

An automatic scanning instrument that is used to study a substance's fluorescence over a wide range of wavelengths. It...

The science that deals with the measurement of optical absorbance (i.e. optical densities) over microscopic areas of a given...

Devices in which the lasing medium is a vapor of metal atoms or ions, sometimes mixed with another gas. Metal vapor lasers...

Also known as Fresnel reflection. That portion of the incident radiation that is reflected from the surface of a refractive...

The re-emission of absorbed energy, having the same wavelength as the incident energy, in an arbitrary direction from a...

A type of multiple-pass amplifier in which no optical leakage is allowed until a finite number of passes has occurred; at...

A modified form of an image-retaining panel that can be used in subdued daylight. This is achieved by adding a layer of zinc...

A test for spherical aberration, coma or astigmatism in which incident rays from a point source are isolated by small holes...

The creation of topographical maps and charts from a stereographic record produced through the overlapping of consecutive...

1. In a cathode-ray tube, the glow surrounding a bright spot that appears on the fluorescent screen as the result of the...

In fiber optics, the glass that is found around the glass core of the fiber, and that has a lower refractive index than the...

Any ray through an optical system that is not a meridional ray. The plane created by a refracted skew ray does not contain...

The luminosity that remains in a rarefied gas after an electrodeless discharge has traversed the gas.

A device utilizing an electron beam for the observation and recording of submicroscopic samples with the aid of photographic...

In compact disc and CD-ROM technology, the portion of the drive that projects the laser light onto the surface of the media...

An optical circuit, either monolithic or hybrid, composed of active and passive components, used for coupling between...

A fixed-focus camera designed to record the ink impression of fingerprints that have been impressed on a card or form for...

A device consisting of a microammeter, a photovoltaic cell and a battery. It is used for the measurement of scene brightness...

A line formed by the principal (center) ray of an oblique bundle of rays.

An instrument similar to the spectroheliograph, but having a scanning method that is performed by a pair of rapidly...

A camera used to reduce originals onto film for easy storage. There are two basic types: one in which the film is fixed...

Device consisting of a laser diode, beam-correcting optics and collimating optics in a single housing. Also called a...

An artificial material, engineered to have a negative refractive index value, such that light or any other form of...

Trade name referring to an instrument that determines surface distances by measuring the length of time it takes for a...

A layer of material applied to a coated surface to protect it from physical or chemical action.

The condition in which the index of refraction in an optical fiber varies as a parabolic function of the radius.

A graph used in photography to portray the increase of a film's density as its time of exposure increases.

A device that combines electronic and optical techniques to form a monitored infrared signal between 1 and 14 µm. It...

A circuit whose passive components are deposited on a given substrate by sputtering or vacuum processes.

A reflecting optic whose reflectivity is a function of the radial distance from the optic axis; can be used to convert a...

The total scattering attributable to the intrinsic properties of the materials through which an optical wave is propagating.

Elastic scattering that occurs when inelastic processes eliminate particles from the beam.

Biometrics refers to the automated recognition of individuals based on their physiological or behavioral characteristics....

The line of vision; the optical axis of a telescope or other observation system. The straight line connecting the object and...

A term describing a type of scratch.

The horizontal distance between the 90° meridian of a bifocal lens and the geometrical center of the segment.

The optical phenomenon that causes relative motion between two objects when the eyepoint is moved laterally. When parallax...

Modulation transfer function of an optical element when used for transporting images from a lambertian source such as...

The method used to measure the index profile of an optical fiber by placing it in an interferometer and illuminating the...

The term reflective is an adjective that describes the ability of a surface or material to reflect light or other forms of...

Electromagnetic radiation with frequencies between 300 GHz and 10 THz, and existing between regions of the electromagnetic...

A small incandescent lamp whose intense beam is focused on the optical soundtrack of a motion picture film. The soundtrack...

A discipline that combines optics and genetics to enable the use of light to stimulate and control cells in living tissue,...

The fluorescent emission spectrum emitted by certain substances following the irradiation of one of these substances with...

In vacuum deposition, a device that removes contaminants from the vacuum chamber.

The change in refractive index that occurs as acoustic vibrations are transmitted through an optical material.The index...

A cosmic phenomenon in which the mass and density of a star pass a critical point so that the escape velocity matches the...

A laser diode module is a compact device that incorporates a laser diode, optics, and often other components into a single...

A spectrophotometer that makes use of filters to isolate narrow bands of the spectrum.

In photography, the layer of light-sensitive material (usually a suspension of silver halide crystals) that coats the film...

The distortion that is the result of viewing a print from a point other than the center of perspective. The center of...

The figure seen through or imaged by an optical system. It may contain structures, natural or artificial, or it may be the...

Measure of a detector's signal during exposure to radiation of a constant power level and varying wavelength.

A glow discharge lamp consisting of a cold cathode and a mixture of inert gases. The intensity of illumination varies with...

An instrument used to detect the fluorescence emitted by a source in comparison with a reference.

The scientific observation of celestial radiation that has reached the vicinity of Earth, and the interpretation of these...

The minimum amount of strength characteristic of an optical fiber, as determined by proof stressing; expressed in thousands...

The formation of transistors, diodes, capacitors, resistors and other electronic elements directly on a flake of silicon by...

A tabulation of predicted positions that have been calculated for one or more celestial bodies or orbiting satellites.

The Casimir force is a quantum phenomenon that results in an attractive force between two closely spaced uncharged...

The combination of two or more different small-molecule monomers into a polymer.

The property of an optical system whereby only the effects of diffraction determine the quality of the image it produces.

GaN (gallium nitride) distributed feedback (DFB) lasers refer to a specific type of semiconductor laser based on Gallium...

An expression of the tolerance of decentration of a laser diode from the optical axis: the region around the axis in the...

The restriction of wavefront error to within a quarter of a wavelength of a true spherical surface to assure essentially...

Anisotropic is a term used to describe a material or substance that exhibits different properties or behaviors in different...

The perceptual term for that aspect of color described by words such as red, yellow or blue. Achromatic colors, such as...

Light interference fringes that can be viewed on a screen near a biprism.

A device used in thin-film deposition; the material to be evaporated is placed in a crucible that is heated inductively by...

A reagent is a substance or compound that is used in a chemical reaction to bring about a specific transformation or to...

An image that is formed when rays emerging from an optical system all converge to a point on the optical axis. A real image...

A Ti:sapphire laser is a type of solid-state laser that utilizes a titanium-doped sapphire crystal as the gain medium. The...

A laser whose output is limited to a single wavelength.

Process for growth of solar cells that results in rectangular shapes consisting of many interconnected cells in a series or...

An optical filter is a device that selectively transmits or blocks specific wavelengths, or colors, of light. Optical...

A device employed to identify toxic agents lingering on the ground or in the air from up to three miles away, by using laser...

The material removed during diamond machining of glass components.

A technique, involving spectrophotometry in the ultraviolet, that is designed to determine the colors of thin-layer...

A unit of luminance equal to 1/p candela per square centimeter. (l).

An Abbe condenser in which the upper lens element is fixed. The lower lens may focus the illumination between the elements...

A crystalline substance in which all planes are parallel, or approximately parallel.

1. Attribute of a visual sensation that permits a judgment to be made of the amount of pure chromatic color present. 2. The...

Diffuse reflectance spectroscopy (DRS) is a nondestructive analytical technique used to investigate the optical properties...

A compound lens so constructed that its overall length is equal to or less than its effective focal length.

A crystal defect that is a combination of a vacancy and an interstitial created by the removal of an ion from a lattice and...

Photon flow created by imaging of light into a detector array; IPD is the electrical signal used by the image processor in a...

The angular width of a radiation beam. With respect to a conical beam of light, it is the vertex angle of the cone. The...

The ratio of energy or intensity absorbed by the medium (numerator) to the total incident energy.

Radiant power per unit source area per unit solid angle. Usually it is expressed in watts/m2/steradian.

A filter fluorometer that uses a photomultiplier tube to detect the fluorescence of a sample.

A man-made satellite that orbits 35,680 km from the Earth at a rate of one orbit per 24-hour period, thereby retaining its...

A plate of glass, usually a photograph, on which there is a central spot surrounded by concentric annular zones, alternately...

The attribute of visual experience that can be described as having quantitatively specifiable dimensions of hue, saturation,...

Mechanical device intended for the translation (rotational and linear) using high precision control from electronically...

The storage surface of an electron beam tube that is scanned by an electron beam to generate an output-signal current...

An assembly of prototype instruments, equipment and/or software designed to perform all the functions of a concept or idea...

A television camera tube in which a low-velocity electron beam scans a photoactive mosaic that has been created by an...

Commonly performed in spectroscopy, the optical null process is a method for radiation detection whereby physical detectors...

A microscope designed so that the specimen is located face down above the objective.

A flexible fiber cable with a small diameter that transports light from the excitation laser to the target. Used in Raman...

A rigid medium, generally a polycarbonate substrate coated with a reflective aluminum layer, that stores information (such...

A data transfer function that moves a rectangular group of pixels between bit maps. Often used in displaying cursors and...

The linear relationship between input and output optical fields for a given optical system or application that allows the...

A lens system in which the centers of curvature of all surfaces fall on a common axis.

A device used to create a light output that exceeds light input, the energy being provided by an electric field. It consists...

A vacuum chamber is a sealed enclosure from which air and other gases are removed to create a low-pressure environment,...

The line that divides the two half-images in a coincidence rangefinder. The two halves of the images formed by the two...

A series of high contrast block letters or similar objects arranged to permit the evaluation of eyesight in humans.

A monolithic laser diode incorporating multiple coupled emitters.

Optical glass that possesses a refractive index equal to or less than 1.5, and an Abbe number that ranges from 62 to about...

The coefficient Å in Angstrom's formula for the dispersing coefficient for dust present in the atmosphere. The formula...

The imaging of two photographs of a stereo pair, in complementary colors, for the preparation of contour maps.

See thermoelectric cooling.

Characteristic of the relationship between photoelectric activity and the wavelength of incident radiation.

The micrometer-size depressions that store data digitally in an optical data storage medium.

Technology that corrects the shape of reflective optics; primarily applied in large telescope systems, in order to...

A vacuum tube in which a magnetic field is superimposed onto the tube's electrical field. When the two fields are aligned,...

A microscope that has an annular stop in the lower focal plane of the condenser, and a quarter-wave retarding and absorbing...

A multimode laser characteristic defined as the ratio of power loss for the second mode to that of the lowest mode.

Also known as a pyrradiometer. An instrument that is designed to measure heat radiation nonselectively; e.g., the...

The pattern formed by a character generation cathode-ray tube system, in which the characters are composed of a sequence of...

Photonic crystals are artificial structures or materials designed to manipulate and control the flow of light in a manner...

In fiber optics, the use of a detector to study the range of refractive indices achieved at various wavelengths. This...

A technique for observing the decay of light emissions from sources following their pulsed excitations, based on recording...

A telescope so manufactured that the image remains erect and the position of the eyepiece is unchanged as the line of sight...

A machining process that uses a laser to cut three-dimensional molds or models.

Coded image obtained optically with a nonredundant pinhole array imaging aperture.

An LCD that has pixels with no internal drive transistors.

An electrophoretic display, often referred to as an electronic paper display or e-paper display, is a type of electronic...

The spreading of potentially equal radiation frequencies that results in broadening of the spectral line. This effect is...

Fluorescence formed when atoms of one element collide with excited atoms of another.

Fluorescence produced as a result of the intrinsic property of the material itself or the doping of the material with trace...

The theory of propagation of energy by combined electric and magnetic fields included in Maxwell's equations.

With respect to photography, the process used to increase the effective speed of an emulsion between manufacture and...

An object that has a sinusoidal variation of luminance. Its image will have a sinusoidal variation of illuminance and the...

A specially designed microscope for observing the etched surface of a polished metal specimen. The specimen is often laid...

The photographic record of the diffracted beams formed when heterogeneous x-rays emerging from a pinhole or slit impinge...

A fiber optic connector or splice that mates two multifiber cables, optically aligning all of the individual fibers...

Holography is a technique used to capture and reconstruct three-dimensional images using the principles of interference and...

An electron tube that has an anode, a cathode, a control electrode and another electrode (usually a screen grid).

Fluorescence lifetime refers to the average time it takes for a fluorophore, a molecule that absorbs light at one wavelength...

Technique of projecting an illuminated target at infinity and receiving the target image after reflection from a flat mirror...

Rayleigh scattering is a phenomenon that occurs when light waves interact with particles or molecules that are much smaller...

Light from a pulsed laser focused into nonsaturable absorbing fluid that generates a strongly backscattered light beam with...

The analysis of the photographs taken from the radar display of a survey aircraft and used when recording terrain that is...

A type of camera that incorporates a tiny mirror that oscillates in accordance with incoming signals. An illuminated slit is...

Having three unequal angles perpendicular to each other.

A camera, with a rotating prism, that is capable of forming multiple exposures on a constantly moving strip of film.

A microbubble resonator is a device used in photonics and optical physics for the precise manipulation of light waves. It...

A device for the internal inspection of hard-to-get-at mechanical parts, such as rifle barrels, sewer pipes, oil wells, or...

A laser whose pulses are expanded, using gratings and optical fibers, before amplification and compressed to increase beam...

A projector designed to give each of the observer's eyes its own disparate image.

A phototube in which the primary photoemission current, before being extracted at the anode, is multiplied many times.

In imaging, the processing of pixel data in such a way that a group of pixels is analyzed at one time rather than one pixel...

A lens with a surface that is a cone instead of the usual sphere.

The formula that gives the wavelength of maximum spectral radiant emittance of a perfect blackbody: λmax =...

A material used as a protective layer on an aluminized or silvered mirror. It is evaporated on the mirror as a thin layer,...

The alteration and reduction of color with the addition of white light. The perceived color shift that occurs as the...

The relative path difference (or phase shift) traveled between two rays that pass through different mediums from the same...

An energy transition concerned with the combination of a photon and a phonon.

A type of ultrasensitive laser spectroscopy that can detect quantities as small as a single atom of some substances and that...

In imaging technology, assigning color to black and white images to differentiate features or convey information. Also...

The analysis of retinal zones in which different hues can be detected. Also called campimetry.

In a liquid crystal system, the director refers to the local symmetry axis around which the long range order of the liquid...

A Peltier cooler, also known as a thermoelectric cooler (TEC) or thermoelectric module, is a solid-state device that uses...

Description of a material, such as a water-soluble salt, that will continue absorbing moisture from the surrounding...

1. An instrument used to measure the opacity or density of dyes, pigments or dispersed particles that form an image in or on...

Optic surface cleaning liquid that may be applied to glass, crystal, dielectric and metal surfaces; however, may not be...

A partially filled or empty energy band through which electrons can move easily. The material can therefore carry an...

The technology that deals with the interaction of organic materials with light and other forms of radiant energy whose...

A phase screen, in the context of optics and wave optics, refers to a surface or medium that introduces a phase delay to an...

A telescope with an ellipsoidal secondary concave mirror that reflects rays from a parabolic primary mirror through an...

Text or images printed on paper or another tangible medium, as opposed to those viewed electronically on a cathode-ray-tube...

Any optical transmission channel used in telecommunications designed to connect two end terminals or to be connected in...

The utilization of photometric measurement to determine the relative magnitudes of the heavenly bodies.

A spectrometric instrument that detects radiation simultaneously in multiple channels, sorts it spectrally from the deep...

A condenser that forms a hollow cone-shaped beam of light with its focal point in the plane of the specimen. If it is used...

Terahertz (THz) refers to a unit of frequency in the electromagnetic spectrum, denoting waves with frequencies between 0.1...

The broadening of a laser's line width in a way that affects every atom (or molecule), and thus the whole system, in the...

In laser damage testing, the exposure of many sites of a sample to different intensities of laser irradiation to discover...

Long-wave infrared (LWIR) refers to a specific range of the infrared spectrum. Infrared radiation is divided into three main...

Also known as OCT-A, optical coherence tomography angiography is an imaging technique that uses light waves to measure...

A laser dye whose absorption coefficient drops at high levels of incident radiation. The phenomenon is often called...

A term describing a substance that is impervious to light; the characteristic of a substance that has no luminous...

In atmospheric optics, the almost total blocking of light transmission in the atmosphere due to the scattering and...

A thermoplastic or optically transmitting hard plastic produced by applying polymerization initiator and heat to a monomer.

With respect to television, the returning direction of the electron beam during the vertical blanking period.

The process of forming a lens to a given pattern, or of cutting a piece of glass along the line of scratch.

In computer graphics, the assignment of each pixel on a display screen to its own switch in the computer memory.

A method of improving the signal-to-noise ratio of an interferogram by adding another interferogram to it.

A type of fiber optic connector consisting of two cone-shaped ferrules aligned by a mating sleeve.

Generic term for read-only optical data storage, source of the Philips-Sony term CD-ROM.

Glass of special composition that is melted, formed into desired shapes, and subjected to a high-temperature treatment in...

A telemicroscope in which a negative eyepiece is used to produce erect images.

A two-lens arrangement intended to image light into a microscope slide sample. The primary aberrations present are red and...

A device that uses a piezoelectric crystal to convert ultrasonic sound waves, transmitted through a subject, into a voltage...

The ability of a camera to compensate in cases where a subject with a large amount of background light would otherwise be...

A still camera with a shutter capable of opening for a time as short as a fraction of a microsecond. An electronically...

Radiation that is emitted by a source outside the Earth and its atmosphere.

Single-mode fiber that preserves the plane of polarization of the light launched into it as the beam propagates through its...

A multilayer filter that passes only a narrow band of wavelengths.

A device that produces an interferogram that can be directly related to the temperature gradient and thereby provides a...

The degree to which the surface of a lens causes an incident ray of light to bend, or the amount of convergence or...

Component that is externally controlled via electronic or photon signal.

A spectrograph having glass as its refracting component and used in cases where speed and high dispersion are not required....

In photography, the density gradient across an edge separating light from darkness, a physically measurable quantity that...

The rule stating that positive uniaxial crystals have greater absorption with respect to the extraordinary component of...

An instrument for the detection of the energy distribution of b-particles and secondary electrons.

A microscope design that involves apertures inserted in conjugate plane positions inside the microscope, with one aperture...

Of all the rays passing through a lens from an off-axis object point to its corresponding image point, there is always one...

1. That portion of the aperture that functions to collect energy and deliver it to the final system detector. 2. For an...

The study and photographing of microscope specimens in ultraviolet light; using an optical microscope containing fluorite...

Exhibiting the characteristic of materials that are electrical insulators or in which an electric field can be sustained...

Name originally given to the sun's infrared radiation by Sir William Herschel in his Philosophical Transactions of 1800.

An electrowetting display (EWD) is a type of electronic display technology that utilizes the principles of electrowetting to...

A signal traveling from transmitter to receiver that has an altered frequency due to the Doppler effect.

Attenuated total reflectance (ATR) spectroscopy is a technique used in analytical chemistry to obtain IR spectra of samples....

The range of materials that, unlike glass, may be used in the infrared. Water-soluble salts, such as cesium iodide, and...

A measurement of the hardness of a material as determined by the penetration depth of a diamond stylus under a specified...

The methods used to determine the extinction characteristics of a medium.

In laser systems, the granular effect that is noted when observing the expanded cross section of a laser beam.

A prism or series of prisms used to disperse a beam of radiant energy of mixed wavelengths into its spectral components.

Topological photonics is a branch of physics and optics that explores the application of topological concepts to the...

The luminescence of an incandescent material.

The indistinct, less luminous portion lying immediately outside an electric arc whose spectrum often differs from that of...

Designed to observe objects below the surface of water. Not to be confused with hygroscopic.

An illuminometer designed to measure illumination in terms of luxes.

In cosmology, a star that exhibits a rapid increase in the magnitude of light, which is followed by a slow decrease in...

A method used to detect internal or residual microstresses in a material by using a laser beam to locate changes in...

A gas maser that is capable of producing radiation in the far-infrared region of the spectrum.

The particular orientation of the image, such as normal, canted, inverted or reverted.

The use of a reflective device, which can be fashioned from a variety of materials including gases, solids, dyes, aerosols,...

An imaging device whose technology contributes three specific advantages: ability to study large solid specimens that...

A curve expressing an optical fiber's total transmitted power as a function of its launch angle at the input.

A device that varies the amplitude and phase of a light beam; e.g., from a laser or by sound waves. Also known as a Bragg...

A radar system that uses electro-optic rather than microwave instrumentation and methods to perform its acquisition and...

The interaction of superimposed light from two separate sources that results in a combined intensity that is less than the...

Quantum dot light-emitting diode (QLED) is a display technology that utilizes quantum dots, which are semiconductor...

An optical testing instrument is a device or system used to evaluate and measure the performance, quality, and...

1. The range of frequencies or wavelengths over which radiations are absorbed or emitted in a transition between a specific...

The low-refractive-index material that surrounds the core of an optical fiber to contain core light while protecting against...

In image processing, a morphology operator in which a structuring element or probe of a particular shape is moved over the...

A photoelectric detector consisting of a glass tube internally coated with a low conductance material. Voltage applied along...

The temperature of a complete radiator that has a total radiant emittance identical to that of an unknown resource.

A material used in photodynamic therapy that is retained selectively by tumor tissue when injected into the body; it then...

Chirality is a property of certain molecules and objects in which they are non-superimposable on their mirror images. In...

The adjustable membrane located just in front of the crystalline lens within the eye. The iris gives the eye its color. See...

A polariscope with a half-shade device and an angular scale generally attached to the analyzer. It is used to measure the...

The auxiliary electrode in a photomultiplier that gives rise to secondary emission and amplification when bombarded by...

The darkening of the laser facet of a semiconductor laser diode. It can be prevented by placing the component in a...

Characterizes a substance whose plane of polarization is rotated counterclockwise as the observer looks through the material...

A photographic emulsion of the silver-halide type that is used to record the path of a charged traveling particle. The...

1. The grinding or edging of a lens so that the geometrical center and optical center do not coincide. 2. The shifting of an...

A form of infrared CCD that utilizes internal photoemission as a photodetection mechanism.

Scanning characterized by the generation of a plane or right circular cone with a vertex angle of about 180° by the...

A device used to control or block a light beam by means of the Kerr electro-optical effect.

Any noise or current fluctuation that prevents precise measurement of the signal current. Both dark current and signal...

A filter that creates spherical aberration resulting in an image with a soft outline.

Near the boundary or edge of the field of an optical system; the outer fringe.

A geometric representation of a light path through an optical device; a line normal to the wavefront indicating the...

A filter that controls the spectral composition of transmitted energy partially by the effects of interference. Frequently,...

The ratio between the focal length of a lens having a longer focal length than that of the standard lens used with a camera,...

A cathode-ray tube that serves as a picture tube in a television receiver. The signal representing the picture intensity is...

A phase reflection scanner that eliminates the need for a complex translation device while maintaining a high-energy-density...

A coherent optical fiber bundle in which the configuration is flat rather than round, giving an output in a line.

Any arrangement of a bundle of optical fibers that alters the shape of the image. For example, by systematic regulation of...

Commonly known as CR39, this thermosetting plastic is used in the casting of eyeglass lenses because of its toughness and...

A term used to denote a concave surface having too long a radius of curvature. That is, its negative power is too small or...

Nonlinear optical materials are substances that exhibit optical properties that are not linearly proportional to the...

Imaging materials that generally consist of a polyester base, a transparent electrically conductive layer and an organic...

A quantum well is a structure in quantum mechanics that confines particles, such as electrons or holes, in one spatial...

Contains elements which produce lasing., e.g. gain medium, oscillator mirrors as well as housing.

The emission of light by thermal radiation of a temperature high enough to render the source of radiation visible.

One of the constants h, k, f or I, used to demonstrate any set of parallel planes in a crystal of the hexagonal system.

The number of bits used to represent a character.

The superimposition of a pilot object on each hologram. The fixed relative position of the scanning and pilot beam during...

A chart, either printed on paper or prepared photographically on glass plates or film, that consists of 3-bar resolution...

The amount of energy required for a particular kind of atom to remove an electron to infinite distance. The ionization...

In image processing, methods of reducing image defects that result from false data. Techniques include sampling, linear...

A subsurface imaging technique based upon the polarization of light reflected off an object. The polarization of reflected...

Lines of equal atmospheric attenuation in a laser beam.

A complete unit containing a light source, globe, reflector, housing, socket and other necessary components for lighting.

A light source that is capable of producing radiation with waves vibrating in phase. The laser is an example of a coherent...

A rotating chamber that can be spun at different speeds to generate great radial forces used to simulate different gravity...

A compound lens, the dimensions and materials of which have been so chosen that the lens is appreciably free of aberrations.

A document-transmitting process that uses a cylinder that rotates the document to be scanned and detected by a photoelectric...

The coherent wave used to play back a recorded hologram. It is identical to the reference wave used in the generation of the...

Specified curved optic intended for maximum collection of light, including off-axis rays, before leaving the exit aperture.

A colorimeter is a device used to measure and quantify the color characteristics of an object or a light source. It provides...

Substances that exhibit the characteristics of both acids and bases and are capable of both P- and N-type conductivity.

Technology that relies on a highly efficient photodetector that can detect incoming light signals at one frequency and...

The section of crystal symmetry having only one-quarter of the greatest number of faces permitted by the crystal system of...

A method of measuring microbending losses in optical fiber by sandwiching a length of fiber between two parallel plates,...

Enhanced picture archiving and communication system (PACS) display (ePAD) is a software tool used in medical imaging to...

Micro-robotics refers to the field of robotics that involves the design, development, and application of miniature robotic...

A fiber optic preform is a cylindrical glass rod or tube used as the starting material for manufacturing optical fibers. It...

A device used to prepare optical fiber end faces; a scribe line made by the cleaver's blade propagates across the fiber,...

Off-axis paraboloid and ellipsoid mirrors are specialized optical components used in various optical systems, particularly...

For an optical table, the amount of displacement that occurs when a heavy load is placed or moved on the surface. To measure...

An instrument for measuring the vertical angle of an object. It usually contains an accurately made protractor, a sensitive...

A pulsed laser having molecular nitrogen as laser material and a wavelength output of 337 nm in the ultraviolet region. It...

A passive infrared system that uses two line-of-sight telescopes to generate both narrow and wide field-of-view images of...

The portion of light scattered when traveling through a unit thickness of material.

The capability of the spatial distributions of incident and reflected flux to interchange completely without alteration of...

A filtering device that detects what is new in a scene of interest. Often compared to that of a temporal high pass filter,...

A bench with instrumentation including a collimator, a microscope, positioners and a nodal slide used to rotate a lens about...

1. Also known as near-field diffraction. The field of radiation sent through an aperture in an absorbing screen at large...

Colors differing only in chromaticity but not in luminance.

A device that uses low-level visible radiation or infrared radiation to produce a visual image of a night scene. These...

A photoconductive cell having greatest sensitivity in the infrared region. The photosensitive material of the cell is lead...

The Foucault test is performed by moving a knife edge laterally into the image of a small point source. The eye, or a...

In vitro is a Latin term that translates to "in glass." In scientific contexts, particularly in biology and medicine, it...

A wide-field multiobject spectroscopy system used in astronomy, in which a bundle of low-loss optical fibers positioned on...

Characteristic of optical correlators in which invariance to more than one distortion parameter per axis of the processor is...

Process developed for the production of high-resolution patterns in electro- and magneto-optics. These high-generation...

A doped or absorbing transparent medium cut or molded into a wedge in order to measure the real and imaginary components of...

A polished plano-parallel plate that is contacted to an unpolished glass surface to permit see-through analysis of the...

The method for measuring the index profile of an optical fiber or preform by illuminating it coherently and transversely to...

A synchrotron is a type of particle accelerator that uses magnetic fields to steer charged particles, typically electrons or...

Light diffracted by a solid (usually quartz in crystal or fused form) traversed by acoustic waves. If the ultrasonic...

The projection of the image beam by a cathode-ray tube through a mask, where it is deflected through the suitable character...

Describing the standard television method of raster scanning in which the image is the product of two fields, each of which...

A temperature-controlled container used to stabilize the temperature and resonant frequency of a crystal found in a...

Technique using a fiber optic assembly to illuminate an opaque object and transmit an image back from it without a lens...

A linear computation or algorithm performed on a selected series in the form of an input signal that produces a new series...

The angle formed between a ray of light striking a surface and the normal to that surface at the point of incidence.

A dark region created by spherical aberration of an eyepiece's exit pupil. Because of the aberration, an observer's eye must...

Literally the opposite of resonance, antiresonance occurs when any variation in excitation frequency results in an increased...

That property of a material that determines that velocity of propagation within the material is the same for all directions.

Also called DLIP, a high-speed, high-resolution processing technique that uses high-power, pulsed laser systems to directly...

A defect in the cleaved end face of an optical fiber in which the surface changes abruptly.

The method of determining the energy distribution of high-speed charged particles by the luminous effect formed when the...

A device used to maintain near-absolute temperatures for experimental procedures.

The dark absorption lines observed in the spectrum of the photosphere of the sun. There are thousands of these lines, the...

The pattern of microwave field intensity that can be obtained by detecting the minute expansion of a microwave absorber slab...

A technique used to store wavefront information on thin polarization information-recordable materials by controlling the...

An electric discharge lamp in which the conducting vapor is that of metallic sodium instead of the usual mercury. It emits a...

A microscope that allows examination of a small crystal and conveniently provides linearly polarized object and reference...

Also known as gas focusing. The introduction of an inert gas into a cathode-ray tube for the concentration of the electron...

Discharge that results when a doped semiconductor crystal with a PN junction is charged with a low-voltage direct current....

An optical source that has a luminous distribution that is uniform for all directions.

Fluorescence lifetime imaging (FLIM) is an advanced imaging technique that provides information about the lifetime of...

A gas laser equipped with Brewster windows and concave mirrors (having unlike reflective properties) at each end of the tube...

Any noise with a power spectral density that is the inverse of the signal's frequency and is therefore most significant for...

An image, real or virtual, whose spatial orientation is identical to that of the object. The image obtained at the retina...

An electron tube whose electrical characteristics will not be affected by gaseous ionization because of its high degree of...

A quantum of electromagnetic energy of a single mode; i.e., a single wavelength, direction and polarization. As a unit of...

A laser warning and countermeasure system containing a sensor that indicates the direction of a laser beam, and analytical...

Hyperchromic shift refers to an increase in the absorption of light, leading to a higher absorbance, often observed in...

The interferometric analysis of a complex object by utilizing the three-dimensional hologram. By causing a laser beam to...

Complex devices, often involving a computer, in which a photograph is scanned by a point of light, the amplitude of the...

A nonlinear label-free imaging technique commonly used during surgical procedures for the visualization of collagen fibers...

Also known as a white-light interferometer. Measures surface texture and shape from nanometer-scale roughness to...

Luminescence that arises from friction and that usually occurs in crystalline materials.

For a pulsed laser, the product of the energy per pulse (joule) and the pulse frequency (hertz); expressed in watts.

Introduced into the laser beam from localized fluctuations in current density within the plasma itself. These fluctuations...

Reactive evaporation refers to a process in thin-film deposition where a material is deposited onto a substrate through...

A device used to measure directional reflectance, with light collection restricted to a narrow range of angles of which the...

The temperature at which the solid phase of a material is in equilibrium with the liquid phase, or when the material changes...

A type of solar eclipse that occurs when the sun is at perihelion and the moon is at apogee. Because the apparent size of...

A camera system used for microphotography that has a structure, such as a cylinder or surveyor belt, to rotate the documents...

A loose term for a single polishing machine. In a lens factory it is the minimum unit of production.

Consisting of, containing, pertaining to or yielding carbon.

Also known as amplification. 1. The increase in a signal that is transmitted from one point to another through an amplifier....

The use of photoelectric sensors to detect and measure the intensity of a light source. This application, as compared to...

That state determining that two waves of like frequency will travel through their maximum and minimum values of the same...

Obeying Lambert's cosine law.

Light generated along the interface when light is incident in the neighborhood of the total internal reflection angle.

An optical element having plane-inclined surfaces. Usually the faces are inclined toward one another at very small angles....

An engine in which work is performed by the expansion of a gas at high temperature; heat for the expansion is supplied...

A high-speed shutter, similar to a Kerr cell, that uses the birefringence produced in a liquid during the passage of an...

The smallest angle through which light is bent by an optical element or system. In a prism, the angle of deviation is a...

A monochromator is an optical instrument used to isolate and select a narrow range of wavelengths from a broader spectrum of...

A strand of aramid yarn, steel or fiberglass in an optical cable intended to prevent bending or stretching that would damage...

Photographic recording of rapid events at a rate exceeding 106 frames per second.

A tiny lens (as small as 100 µm in diameter) used to focus light on charge-coupled devices, formed by heating a...

Any problem that requires retrieval of the distribution of some internal properties, such as temperature concentration,...

A camera containing an electronic image sensor that converts the image to an electronic signal suitable for television...

An electric discharge between two carbon rods that are touched together to start the arc and then separated slightly. The...

A process and method by which manipulation and orientation of a given number of directed laser beams decreases the motion of...

The emergence of a ray along the normal to the emergent surface of a medium.

A shutter in which the opening and closing times for a large aperture setting occupy a substantial fraction of the total...

A measure of image quality produced by an optical system. May be specified in terms of cycles per millimeter, referencing a...

A set of algorithms used to study the structural and spatial characteristics of objects in a digitized image for...

The instrument used to analyze a pulsed electromagnetic wave to determine its time, amplitude, duration and shape, and to...

Neuromorphic refers to the design and development of computing systems or devices that are inspired by the structure and...

A stationary noise that occurs for visible light photodetection when a steady light source, such as a heterodyne reference...

A prism invented by William Nicol in 1828 that is made of calcite, the end faces of which are ground to an angle of 68°...

A rotating mirror coupled with a distant mirror and used in a system by Foucault to compute the velocity of light. Light...

A method of lasing in which free electrons in a laser-produced plasma collide with neonlike ions to excite electrons to...

A graphical device used to measure prism power.

A condition in which an emergent ray is perpendicular to the normal of the emergent surface of a medium.

A technique that uses a solid-state laser and a detector to determine an object's relative distance to the system. The laser...

The region at the PN junction in a semiconductor radiation detector where the potential energies of the two materials create...

Characteristic of radiation detectors that produce energy that is similar to the energy of superconductive gaps when...

A sensor module used in advanced pattern recognition systems, containing signal-processing integrated circuits stacked and...

At a given modulation frequency, wavelength, and for a given effective noise bandwidth, the radiant power that produces a...

A device for forming at least two adjacent areas of polarized light. The angle between the directions of vibration of the...

Analysis of the reflection spectrum that allows the determination of the experimental dielectric function.

Noise generated within an optical communications system link that has both internal (dark current) and external (background...

A type of electron microscope in which the specimen also serves as the cathode source.

A process by which high-quality fiber optics are made. See axial vapor-phase deposition.

An instrument used to recognize and identify incident radiation by the ionizing or stimulating properties of the radiation.

Nanoimprint lithography (NIL) is a nanolithography technique used for fabricating nanoscale patterns on a substrate. It is a...

Referring to compound semiconductor materials combining one element that has three valence electrons with one or more that...

The deflection of an electron beam by the action of an electrostatic field that has a component perpendicular to the...

A contraction of quasi stellar. An astronomical object that appears to be a star but has a different, larger redshift.

Sets of paired lines carefully designed to give the most accurate pointing possible for various lengths of sight.

For a lens with an obscured or noncircular aperture, the focal length divided by the effective aperture.

A hologram in which the image of an object, or the object itself, is located near the hologram recording plane, for optimum...

The range of angle or solid angle values by which light may enter an optical system.

A unit of energy equal to the amount of energy absorbed by one molecule of material undergoing a photochemical reaction, as...

Also known as the Wiener spectrum or the noise power spectrum, the optical power spectrum is a fundamental quantity in...

Broadening of a laser's spectral linewidth when the resonance frequencies of the atoms (or molecules) of the medium are not...

The process of mapping the infrared emittance of an area through the use of an infrared detector and related scanning...

An optical gate typically refers to a device or system that controls the transmission of light, allowing it to pass through...

Also referred to as physical optics - the area of optics in which the wave nature of light is essential when defining its...

A prism that inverts and reverts an image while deviating the line of sight by a 45° angle.

A microscope in which laser light is delivered through single-mode fibers that replace the pinhole usually used in confocal...

A semiconductor laser in which the naturally occurring broad linewidth has been narrowed by incorporating the laser diode...

A process in which a mixture of one or more monomers, plus a catalyst, polymerize under exposure to light radiation....

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...

A method in optical character recognition in which a mobile light beam scans the outlines of characters for subsequent...

With respect to a crystal, a monoclinic crystal consists of three unequal axes, two of which intersect each other obliquely...

Mathematical compensation for the nonhydrogenic behavior of recombination radiation levels of gases, based on the quantum...

A type of birefringent filter, similar in principle to the Lyot filter, consisting of many identical birefringent elements,...

The correlation of radiation between the phases of monochromatic radiation emanating from two separate points.

Pushbroom scanning is a technique used in remote sensing and imaging systems, particularly in satellite and aerial sensors,...

A surveying device used to measure vertical displacement of target centers of scale lines from a horizontal plane generated...

Spectral flow cytometry is an advanced flow cytometry technique that expands the capabilities of traditional flow cytometry...

In optical communications, the translation of optical signals into radio signals, lowering their frequency in detection from...

Gallium nitride (GaN) is a compound made up of gallium (Ga) and nitrogen (N). It is a wide-bandgap semiconductor material...

The distance between the base and the vertex before the edging of a prism.

Two stars so close together that they cannot be resolved by telescopes. They are proved to be double stars by the doubling...

A dichroic coating, also known as a dichroic filter or dichroic mirror, is an optical coating designed to selectively...

A plate made up of thousands of glass fibers arranged parallel to one another, i.e., in a coherent bundle, and fused...

1. The term used to describe any of the many instruments used to remotely record physical dimensions, such as strain,...

In image processing, a device that transforms the digital data into an analog video image that can be viewed on a monitor or...

The study of the physics of x-rays, where the x-rays exhibit properties similar to those of lightwaves. Also called Roentgen...

A form of binary notation that includes a third code representing a stop between bits.

The radiation spectrum of matter found in condensed states, liquid or solid, that is continuous and not a line spectrum. The...

Optical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or...

A means of determining a prism's index of refraction by placing the prism so that its emergent face is perpendicular to the...

Nanophotonics is a branch of science and technology that explores the behavior of light on the nanometer scale, typically at...

In image processing, mathematical operations that change spatial geometry, as for instance scaling, translating, rotating or...

See digitizer; frame grabber.

A pinhole camera used to record a radioactive tracer's distribution in a subject by means of a scintillation counter or a...

One of the first lasers to find practical application. Generally, the pumping mechanism is an electric discharge, although...

Radiation that occurs perpendicular to the plane of the radiation device.

A solar cell that is lightweight and flexible because of its construction by vacuum deposition of a semiconductor material...

The distance between the surface of a ferrule and the surface of a fiber end, provided that the ferrule extends above the...

An aerial photograph produced when the optical axis of the camera is perpendicular to the surface below.

The point at which decreasing current supplied to a laser results in the extinguishing of the laser discharge.

Aplanatic points refer to specific points in an optical system where certain aberrations, such as spherical aberration or...

A chemical detection technique used to measure molecules that have a magnetic dipole moment. The analysis is directed to...

A glow-discharge tube in which the discharge takes place in the conical or crater-shaped depression at one end of the tube.

A bandpass filter with piezoelectric crystal components for the passage or impedance of electrical signals of various...

A photographic recording of interference patterns between a plane wave and a spherical wave on a high-resolution...

The study concerned with the stimulation of chemical activity by laser light as a result of the absorption of photons by a...

Also duty factor, duty ratio. The product of the pulse duration and the pulse repetition frequency of a wave composed of...

An optical coupling device that uses light to bridge the gap between incompatible wire communications systems. It contains...

An exposure meter designed to measure the light striking an object and used at a suitable location in a scene.

Laser active elements typically refers to the substances or materials within a laser system that play a critical role in the...

An approximated measure of the smallest change in color temperature detectable by the human eye, defined as the reciprocal...

The transmission of light by a condenser to observe either very small particles or very fine lines with a microscope.

Common name for a variety of adhesives used for lens bonding, fiber optic splicing and other photonics applications. The...

An artificial star used to aid in adaptive optics imaging of the sky. The guide star is provided from a telescope system on...

The characteristic of displaying three colors when observed in as many separate directions.

Vision at intermediate levels of luminance between photopic and scotopic vision, where both retinal cones and retinal rods...

In avalanche photodiodes, the point at which an increase in the reverse bias voltage causes the current gain to approach...

Optical surface damage due to abrasive rubbing. Abrasion damage affects are less than the thickness of the optical coating...

Modulator/demodulator. An electronic device that modulates and demodulates signals transmitted over communications lines.

A specific form of phase shifting interferometry - commonly referred to as multiple wavelength phase shifting interferometry...

The distance between the center of the two concentric circles of an optical fiber that designate the diameter of the...

Property of a substance whose volume elements differ in composition and optical properties.

Camera designed for the imaging of the earth's surface in order to obtain high quality aerial images

A device used in a free-electron laser to convert the electron-beam's energy into microwave laser radiation by creating a...

Laws that predict the maximum power output as a function of tube diameter for a hydrogen cyanide laser of a given discharge...

The direct influence of light on the magnetic susceptibility of particular materials.

Device used to measure the numerical aperture of a microscope, composed of a 14-mm-thick glass block with numerical aperture...

A polarizing beamsplitting prism similar in design to the Rochon prism. However, the Senarmont transmits the extraordinary...

The fraction of incident light power in an optical modulator that is available to the output beam.

A type of adsorption in which the adsorbed layer is attached to the adsorbent surface by an attractive force between the...

The angle between an instrument's line of sight and a reference horizontal plane.

The function that characterizes the quality of an optical system by denoting the modulation and spatial phase shift of the...

The process whereby a rotating wheel carries grains of an abrasive, suspended in a vehicle, across the surface of the...

The removal of a slight overlap that may be found on a blank or pressing.

A naturally occurring crystalline mineral that has the property of polarizing transmitted light. It is little used now that...

An optical filter so constructed that the density increases progressively from one end to the other, or angularly around a...

The energy in a medium per unit volume.

A chemical compound that exhibits a reversible change in its absorption spectrum upon irradiation with given wavelengths of...

Not spherical; an optical element having one or more surfaces that are not spherical. The spherical surface of a lens may be...

A contraction of "excited dimer." The term refers to an excited species made by combination of two identical atoms...

The term delta error (delta-E) generally refers to the difference or change in error between two values or states. The word...

A miniature projecting device designed to enhance and reproduce the image generated by a smaller image-forming instrument....

A technique used for noncontact inspection of semiconductor wafers. The material is illuminated by an excitation source that...

The plane diagram produced by plotting one of the three chromaticity coordinates (X,Y,Z) against another. The most common...

The reduction in luminance of a light beam due to absorption and scattering as it passes through the atmosphere.

Spectra can be conveniently recorded on photographic film or plates. The portions that are occupied by regions of the...

A device used to accelerate the electrons in a free-electron laser by supplying electrical energy to the electron beam...

Also known as TEA laser. A coherent optical source with a wide wavelength range in the infrared, visible and ultraviolet...

A junction between semiconductors that differ in their doping level conductivities but not in their atomic or alloy...

A sensitometer having a continuously controlled monochromator to measure spectral sensitivity and contrast of photographic...

An optical channel monitor (OCM) is a device used in optical communication systems to monitor and analyze the performance of...

A corner reflector that provides an increase in the range of angles over which it may be used.

Very small phosphor particles present on the screen of a picture tube.

A system by which consumer products are assigned a bar code that is read by a scanner at a cash register, enabling...

The production of rough glass lens blanks that are pressed while red-hot to the approximate size and shape of the finished...

An analytical technique used to determine the nature of extremely small samples by forming the x-ray spectrum of the samples...

Technology that uses data from an array of sensors, one of which is commonly lidar, to solve the problem of creating a map...

1. The near total absorption of plane-polarized light by a polarizer that has an axis perpendicular to the plane of...

The probability that an atom in one state will move spontaneously to a lower state within a given unit of time.

The portion of a glow discharge tube that permits little or no light transmission.

The mathematical expression of the probability of any given state of energy being occupied when a semiconductor is in...

A microscope designed with two eyepieces (oculars), permitting the use of both eyes when viewing through the instrument.

Motion of a fiber into and out of the ferrule. This effect is often caused by changes in temperature.

An optical device used to monitor movement of the human eye.

The force exerted on a surface by radiation.

Radiation similar in origin to spontaneous emission but determined by the presence of other radiation having the same...

The emissivity of a body times the emissive power of a blackbody at the same temperature. For a blackbody, it is the total...

A fiber optic gyroscope (FOG) is a type of gyroscope that uses the interference of light waves to detect changes in...

Observed lengthening in wavelengths of the optical absorption edge of a semiconductor with the application of an electric...

A plasma produced by the interaction of an intense laser pulse with a material surface. Production of ionized particle with...

A method for detecting vibration amplitudes analogous to image holography, except that the film emulsion is replaced by a...

The generation of a difference in electric potential between two electrodes when radiation is incident on one of them.

That point in a Gaussian beam where the wavefront has a curvature of zero and the beam diameter is a minimum.

An arranged series of coils, magnets or electromagnets disposed in such a way that the resulting magnetic fields generate a...

A chart of an x-ray diffraction pattern.

Medical diagnostic (x-ray) imaging using laser printers to produce high-resolution digital hard copy instead of film exposed...

A mechanical or electrical-electromagnetic device for periodically interrupting or blocking abeam of light for a brief known...

A light absorbing material applied to ground optical surfaces during the process of making that surface non reflective. Such...

Gram-positive bacteria are a group of bacteria that have a thick cell wall composed primarily of a substance called...

A computing paradigm that attempts to process information in a manner similar to that of the brain; it differs from...

A process used in document copying and printing that involves the visible rendering of an invisible electrostatic image on a...

The time it takes a cathode-ray tube's electron beam to return to its starting point after completing one line, one field or...

The interaction between electrical and mechanical stress-strain factors in a material. When piezoelectric crystal is...

A family of semiconductor switching devices of which the silicon-controlled rectifier and the triac are most commonly used....

A mappable surface feature arranged in straight or curved lines that is distinguished from surrounding surfaces and is...

A condition in which the solid inclusions within a glass blank are very numerous, such as 25 or more to the square inch.

A ruticon is an opto-electronic device in which light going through it can be modulated by an electric field. The...

A cathode-ray tube having a screen that is coated on the back with a thin film of aluminum, which serves to intensify the...

An instrument used to measure backscatter as well as optical return loss and reflectance within an optical fiber system by...

State typically studied in liquid crystals in which the dielectric coefficient parallel to the director is less than the...

The image of a point source that appears as a circle of finite diameter because of defocusing or the aberrations inherent in...

A computer architecture used in parallel processing whereby the processing elements are directed by a single, central...

Also known as single plane illumination microscopy (SPIM), this process was designed for imaging of sensitive samples and...

A display in which regeneration takes place serially at a fixed speed in a set pattern through the scan lines.

The phenomenon that makes nonlinear the mathematical expression for the electrical polarization of a medium through which...

In fiber optics, the annular region between two concentric circles; used to specify fiber cladding and core sizes.

Factor that relates the pulse spread occurring in a graded-index fiber to that of an equivalent step-index fiber having an...

A defect in infrared systems that appears as a dark circular area on a displayed image, caused by radiation reflecting into...

A scintillation crystal, also known simply as a scintillator, is a material that emits light when it interacts with ionizing...

A pollution-measuring device used to detect the presence of nitric oxide regardless of other gases present. It utilizes the...

A window made of glass containing a high percentage of lead or other dense material known to absorb x-rays readily.

The radiation emitted in semiconductors when electrons in the conduction band recombine with holes in the valence band. If...

Single-molecule Förster resonance energy transfer (smFRET) is a specialized technique in biophysics and molecular...

A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics....

A range of wavelengths within which radiation transmitted through the atmosphere suffers relatively little absorption by...

Stress applied to an optical fiber at a constant rate.

In optics, the conduction of radiant energy through a medium. Often denotes the percentage of energy passing through an...

A doubly refracting mineral used to produce polarizing prisms. It is uniaxial negative and in the trigonal division of the...

The distance between two focal lines in an astigmatic image produced by a lens or mirror.

A photometer that uses a set of color filters to measure the intensity of light in various regions of the spectrum.

An optical switch that controls conduction paths into and out of a junction in fiber optic and integrated optical circuits.

A semiconductor device with the property of conducting current more easily in one direction than the other. It has two...

A system designed with a laser as a light source and a means for producing sound waves extending beyond 100 MHz to deflect...

A type of phase-shift keying using a one-bit delay line.

An electrically conductive layer for carrying off static charges that might accumulate on a surface.

A diode electron tube that contains a heated cathode.

The property exhibited by certain birefringent crystals in which the degree with which they transmit polarized light is...

A camera that uses a rotating mirror to project sequential images onto lenses that are arranged in an arc. The reflected...

A free-electron laser (FEL) is a type of laser that generates coherent, high-intensity electromagnetic radiation by using a...

Continuous wave (CW) refers to a type of signal or transmission where the signal is constant and does not vary with time. In...

A luminous display of numbers and the letters of the alphabet.

The ratio of the number of bits received incorrectly to the total number of bits transmitted digitally in a system.

The term sometimes used to describe the sequential arrangement of components in a video system -- from transmitter to...

Optical components exceeding 24 in. in diameter. The components are usually glass, acrylic or polystyrene and are used for...

Essentially, a hologram of a hologram, in which the first-generation hologram is masked with a narrow slit. During image...

A radiation detector with its active medium mounted within a lens that focuses the radiation signal. The improvement in...

The angular relation between two light rays that originated at the same object point. Sometimes used to indicate the angle...

A photonic crystal surface-emitting laser (PCSEL) refers to a type of laser diode that emits light from its surface rather...

In image processing, the enhancement of an image by increasing or decreasing its spatial frequencies.

A form of mirage where objects near or just below the horizon appear in enlarged or distorted form because of atmospheric...

A waveguide that has a core with a lower refractive index than the refractive index of the cladding. This structure can...

1. A defect inherent in a multiple-axis positioning system whereby an adjustment of one axis causes an undesired change in...

For each mode in an optical waveguide, the term used to describe the process by which an electromagnetic signal is distorted...

1. A piece of glass with plane parallel surfaces used to admit light into an optical system and to exclude dirt and...

A transition boundary between two regions having different properties in a P-type semiconducting material.

A multilayer antireflective thin-film coating, so called because its reflectance rises steeply at wavelengths above and...

A container that prevents spliced fibers from becoming damaged or being misplaced.

An emulsion in which grains of the photosensitive material silver halide are deposited. Each grain, when exposed to light,...

Astronomical detector consisting of a photocathode isolated from the target by a coin value from which electrons are focused...

A narrow cone of light rays that diverge from a point source or converge to an image point.

A crimped metal cylinder that holds the connector to the cable through the cable's strength member.

Instrument that uses absorption spectroscopy to detect gases in planetary atmospheres. Dispersed incoming radiation is...

The amount of energy required to raise the energy level of an atom; a necessity if the atom is to radiate energy. High...

Optical fiber is a thin, flexible, transparent strand or filament made of glass or plastic used for transmitting light...

A computer-generated routine for achieving true-temperature readings in thermal infrared imaging systems.

A laser cavity, also known as an optical cavity or resonator, is a fundamental component of a laser system. It is a confined...

Broadband radiation emitted by a laser that does not transmit through the optical element. It can be removed by filtering.

Present in photocurrent burst, it is the low frequency pulse that corresponds to the light scattered from the beams in the...

The position and shape of the image of a point source, as predicted by geometric optics alone. The geometric image is to be...

The center of a local area network in the star topology.

Also known as aplanatic lens. A lens corrected for spherical aberration and coma.

Ultrasonic refers to sound waves with frequencies higher than the upper audible limit of human hearing, typically above...

A means of adjusting the sharpness of an image automatically, with a sensor for estimating distance or contrast and a drive...

An electronic device that minimizes short-term drift effects and random measurement error inherent in alternate...

Ratio of the directionally reflected flux to that reflected in the same direction by a perfect reflecting diffuser...

A technique used in radiography to obtain an unblurred image of a moving object by the use of very short x-ray exposures,...

A plane that lies at right angles to the tube axis that has the deflection center.

A polarizing prism formed from calcite that is like the Nicol prism but has the two parts divided by a thin air-film and cut...

Experimental method of measuring the transmission of a given sample as a function of the wavelength.

Also known as a shadow mask, a perforated plate placed between the focusing and accelerating electrodes, and the tricolor...

Pertaining to radiation or particle emission, whereby the emission is produced with minimal energy spread.

The phase change of one of the two split beams of an interference microscope.

A phase-modulated sensor is a type of sensor that uses modulation of the phase of a signal to measure changes in a physical...

A type of optical fiber in which a silica core is surrounded by a hard polymer or similar material much stronger than the...

Radiant power emitted into a full sphere (4p steradians) by a unit area of a source; expressed in watts per square meter.

A mounting used for large concave gratings, whereby the slit, grating and plate holder lie in the Rowland circle, and the...

A device for extracting a portion of the optical signal from a fiber.

An electron-gun system is an assembly used to generate and control a focused beam of electrons. Electron guns find...

The production of a block by attaching the optical elements to a plate by means of individual buttons of pitch or other...

The nondestructive analysis and recording of industrial components based on the absorption of relatively low-energy neutrons...

A glass filter that transmits visible light while absorbing infrared energy (heat).

A type of glass used in near-infrared optical components, in which germanium is used as a cation instead of silicon.

Refers to micron-size complex machines that have physical dimensions suitable for the fabrication of optical switches for...

Variations in signal detected on a bolometer that are caused by instabilities in the temperature of the sky.

The gradual decrease over time in output signal with constant input light level.

A method of spectral analysis in which some property of the sample is varied and the corresponding change is measured. The...

An electron beam gun in which plasma that is generated within a low-voltage hollow-cathode discharge serves as the source of...

Also called color blocking. The formation of a block by making optical contact between a number of optical elements and a...

The small central portion of the human retina that is responsible for providing the clearest, and most distinct aspects of...

An infrared imaging device composed of a detector array and readout electronics. It may include a cryogenic cooling system....

A polymer produced as a result of photochemical processes.

A forerunner of the modern camera, this instrument had a focusable lens that produced a sharp image on the enclosure...

A point cloud is a set of data points in a three-dimensional coordinate system, where each point represents a specific...

Laser drift typically refers to a phenomenon where the frequency or wavelength of a laser source gradually changes over...

A technique based on the principles of laser trapping and used to manipulate the position of small particles by gradually...

The force that stimulates the emission of an electrical current when photovoltaic action creates a potential difference...

A wedge-shaped piece of quartz typically found in a polarimeter to monitor and rotate the plane of polarization of plane...

Describing a surface that is coated with a film of metal of such thickness that it transmits about one-half of the incident...

In optics, the production of maxima and minima by the superimposition of two sets of interference fringes from light of two...

The formation of an interferogram by means of two holograms on the same recording medium, often used for determining small...

An excimer laser is a type of ultraviolet laser that emits short pulses of light in the ultraviolet spectrum. The term...

In optics, a shape often given to the leading edge of a projectile. In any side view it appears as a pointed arc, while any...

The circle of confusion is a defocused or aberrated image of a point. Focus is generally set where the diameter of this...

Technique for the precision evaluation of coincidence of a laser beam's center with the edge of the object under study and...

A measurement method for reflectance by gas ionization in which light passes through a vapor before and after reflection....

Scientific complementary metal-oxide semiconductor (sCMOS) refers to a type of image sensor technology specifically designed...

A device that enables visual tracing of a fiber optic cable to check for breaks and defects by coupling visible light into...

A scanner in which a fiber optic assembly replaces a lens system.

Any of the various methods of decomposing a signal into a set of coefficients of orthogonal waveforms (trigonometric...

A strip or annulus of glass coated with a semitransparent material such as inconel. The coating thickness, and as a result...

The concept of the de Broglie wavelength exploits the wave-particle duality of quantum physics by associating all matter (of...

Also known as light beating. The mixing of two narrowband optical components to produce an AC component in the photocurrent...

Phase distortion refers to a change in the phase relationships between different frequency components of a signal. In the...

Automated optical inspection (AOI) is a technology used in manufacturing processes, particularly in electronics, to...

A prism having several plane polished surfaces, some to transmit light, some to reflect light, and some to serve both...

Two simple meniscus lenses arranged symmetrically on either side of the aperture stop, providing reduced coma, lateral color...

A gyroscope is a mechanical device consisting of a spinning disk or wheel mounted on a spinning axis in such a way that its...

A small instrument containing a picture support and a pair of magnifying lenses so arranged that the left eye sees only the...

This results from the simultaneous absorption of two photons, each having half the energy needed for excitation and...

A high-speed network or subnetwork that provides a connection between servers and data storage devices.

A system in which a supplied signal causes the deflection of the electron beam in a cathode-ray tube, thus forming a visible...

The ability of the instrument to separate wavelengths that are close together, numerically equal to the ratio of the shorter...

In optics, the mechanical tension, compression or shear in optical glass due to internal stress caused by improper cooling...

A state in which the human eye has very little or no power of accommodation. A common and normal condition in the eyes of...

The use of mathematical analysis to derive solutions in the science of photogrammetry.

A polarizing prism consisting of two calcite prisms cemented such that they deviate the two emerging beams (which are...

The spectrum produced by the interference of light provided that the source used to create the interference has a broad...

A small region within a single crystal where the molecules form a perfect lattice.

The resulting interference pattern generated from moiré deflectometry, the moiré pattern is a pattern...

A sensor generally used for infrared imaging. It consists of two chambers separated by a thin, blackened membrane. An...

A device, optical or electronic, that may be joined to a camera so that the operator may perceive the scene as the camera...

An arc flash is a sudden release of electrical energy due to an electric arc — a continuous, high-current discharge of...

The ratio of reflected flux to incident flux. Unless otherwise specified, the total reflectance is meant; it is sometimes...

A ray that is reflected into the core of an optical fiber from the outer surface of the cladding.

That part of the cladding wherein the refractive index is constant within a specified tolerance, as a function of radius.

A system that uses infrared detectors and related instrumentation to determine when abnormal amounts of infrared radiation,...

Reflection losses incurred at input and output of optical elements because of the difference in refractive index between...

The term "Rydberg atom" refers to an atom in a highly excited state where one or more of its electrons are in a Rydberg...

An interferometric technique for the generation of precision gratings that allows for sequential exposure of small segments...

Also referred to as the opposition surge, the opposition effect is a photometric phenomenon in which a rough retroreflective...

An angstrom, symbolized by the Ångström or Å, is a unit of length used to express atomic and molecular...

Spectrophotometry in which radiation of two separate wavelengths, usually one in an absorption band and the other not, pass...

A nonluminous area around a negatively charged probe that is inserted into the positive column of an arc or glow discharge.

The internet of things (IoT) refers to a network of interconnected physical devices, vehicles, appliances, and other objects...

A quadrivalent semiconductor material, with electrons as the majority charge carriers, that is formed by doping with donor...

The degree to which a pixel in a digital image represents the analog brightness of the corresponding point in the original...

Heatless light emissions from living organisms caused by the combination of oxygen and pigments such as luciferin.

Etaloning is an optical phenomenon that occurs in imaging systems, particularly in devices such as spectrometers,...

The number of electrons that each pixel of a charge-coupled device can hold without overflowing and causing blooming.

A hologram formed by reconstruction of multicolor wavefronts. The system used to produce the hologram is designed to combine...

The technology of manipulating light on a micro scale. In optical communications, this is usually accomplished using two or...

An opening or hole through which radiation or matter may pass.

The ratio of the radiant power transmitted to the second surface of a medium to the corresponding radiant power that has...

A method used in surface quality testing for accurate positioning and rotation of metal spheres about an axis or fixed point...

Radiation emitted from vibrating charged particles. A combination of oscillating electrical and magnetic fields that...

Any pyrheliometer that has a filter placed over its sensor to limit the range of solar radiation it will detect; used to...

An image converter that produces a visible image based on the infrared emittance of the object. The infrared energy is...

A signal, generated by an oscillator, that provides the means of synchronization of operations in a data communications...

The flat or angled surface, usually fine-ground, that limits the aperture of a lens or prism surface.

The phenomenon whereby certain crystals exhibit spontaneous electric polarization. It is analogous with ferromagnetism.

An observed effect of the ability of certain atomic particles to pass through a barrier that they cannot pass over because...

A device containing two photocells behind deep red and blue filters to measure color temperatures. The amplifier gain is...

Tip-enhanced Raman scattering (TERS) is a powerful technique that combines Raman spectroscopy with the enhanced spatial...

A mirror blank refers to the initial piece of material from which a mirror is made. It is typically a flat or slightly...

Luminous flux emitted per unit area of a source, expressed as lumens per area.

A permanent, transparent, and highly transmissive adhesive capable of withstanding extreme temperatures that is applied to...

The lens located at the object end of a microscope tube. A wide range of objectives is available, including simple...

A device that responds to incident light but does not generate light.

The permanent uniting of two glass pieces by high-temperature heating.

With respect to laser radiation, the subjection of the human eye to all or a portion of the laser beam.

The intensification of a latent image, because of exposure to light to which the emulsion is otherwise insensitive.

Able to rotate the plane of polarization of a transmitted, plane-polarized light beam clockwise as seen by a viewer looking...

System of information coding in which the signal is sampled 8000 times per second and the samples quantized by referring...

The phenomenon observed by A.H. Compton in 1923 -- that some scattered radiation possesses a longer wavelength and...

A material having refractive indices that can be altered by an applied electric field.

Radiation from the sun that is made up of a very wide range of wavelengths, from the long infrared to the short ultraviolet...

The effect produced by electrical charges or fields alone, without interaction with magnetic influence.

Designed for the function of optical wavefront analysis. Shack-Hartmann camera aberration sensors use a lens array to image...

A common form of high-precision, ceramic-based actuator capable of moving and measuring at the nanometer level.

Abbreviation of "synchronization.'' In television, the timing signals used to drive the scanning process. Horizontal...

A sealed, hard, magnetic disc drive used for the storage of data in a computer system.

A short focal length (less than five inches) positive lens used to produce a magnified image of the object being viewed....

Radiation used to excite an optical or laser material to a higher energy level. See optical pumping.

Azimuthal polarization refers to a specific polarization state of light where the electric field vector of the...

A two- or three-dimensional space grating formed when ultrasonic beams with varied paths of propagation intersect.

A frame taken with a CCD camera over an exposure length of zero seconds with the lens cap on or the shutter closed and no...

Total number of characters available to each position of a digital numeric system.

The measure used in vacuum technology to quantify the total pressure capacity of the ferrofluidic seal before it fails.

Image displacement by a decentered lens, rotated on a chuck whose axis of rotation passes through the geometrical center of...

A confocal resonator, also known as a confocal cavity or confocal laser resonator, is a type of optical resonator...

A handheld navigational instrument used to measure the elevation angle of celestial bodies such as the sun. An image of the...

A measurement in optical thin-film coating processes whereby the gases remaining in the vacuum chamber after coating are...

A small television tube originally developed for closed-circuit television. It is about 1 inch in diameter and 5 inches...

A lens having one or more toric surfaces. A toric surface is one having a maximum power in one meridian and a minimum power...

In imaging technology, a device that converts raster or line-scan data to pixel form for further processing.

In optics, the total radiant energy incident on a surface-per-unit area. It is equal to the integral over time of the...

A lens or lens surface that is a combination of a sphere and cylinder.

A spectrophotometer is a scientific instrument used to measure the intensity of light at various wavelengths in the...

A precise telescope set on a pair of rotation axes, the horizontal and vertical axes equipped with two divided circles. One...

Translucent collector developed to compensate for the partial blocking of a flat surface's collection angle that normally...

Mathematical definition for the changes that occur between potential and kinetic energy. These formulas express wave motion.

An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot onboard. UAVs are remotely...

A densitometer having a receiver that indicates when a desired radiation level has been attained.

A transparent lead-lanthanum zirconate titanate ceramic with optical qualities that can be controlled by applying voltages...

Also known as mesosphere. A level of the atmosphere, extending from the stratosphere to the ionosphere, that is noted for...

A photon jet is a narrow, highly collimated beam of light that is formed when light interacts with small dielectric...

A spectrophotometer specially designed to measure spectral reflectance.

The photographic recording of the heat radiation emitted from various points on the object as corresponding density...

The name of the mixture of liquid and grinding or polishing compounds used in processing optical materials.

A shallow, fine-pitch diffraction grating having a precise dielectric overcoating that experimentally has absorbed...

A rapid change, as opposed to a long-term drift, of the emission wavelength of an optical source. Chirping is most often...

A medical imaging device that uses a ring of crystal/photomultiplier tube assemblies encircling the patient to detect gamma...

The outside or covering layer.

A cement used to reduce crosstalk in fiber optic bundles or plates.

A fiber-coupled LED (light-emitting diode) refers to an LED device that is optically coupled to an optical fiber for the...

That element of a spectrum line in scattered radiation having a frequency equal to that of the corresponding incident...

Nanoparticle photonic resonator absorption microscopy is a microscopy technique that combines the principles of photonic...

The dielectric coefficient parallel to the director in a liquid crystal display (LCD), rather than perpendicular to the...

The ratio of the lens aperture to its focal length (1/f/#).

The gas of charged particles that begins approximately 50 km above the surface of the Earth and contains a sufficient...

The dispersion attributable to the wavelength dependence of the refractive index of the material used in any optical...

Having the property of color.

A CRT screen on which two phosphors differing in color and persistence are deposited.

An arc discharge tube having a grid that is used to start the discharge through an atmosphere of inert gas or vapor at low...

Light transmission involving no scatter.

Term applied to laser technology to denote an area of above-average intensity often attributable to atmospheric...

Flux per unit solid angle.

The ratio of radiant energy reflected from a rough surface to that incident on it. Usually, the radiant energy is total...

A photovoltaic cell, commonly known as a solar cell, is a semiconductor device that directly converts light energy into...

A display format consisting of small light-emitting elements arranged as a two-dimensional array. Various elements are...

A microcircuit whose passive components consist of a ceramic-metal combination deposited on a given substrate by screening...

A small mirror, sometimes plane and sometimes concave, attached to the rotating coil of a galvanometer to cause a spot of...

The combination of two waves having the same frequency and amplitude and traveling in opposite directions. Standing waves...

Mod Method of obtaining precise temporal mode characteristics.

One surface of a nonconducting plate that is coated with many minute particles of photoemissive material that are insulated...

A lens derived from the Cooke triplet anastigmat, but with one of the crown elements split in two, resulting in improved...

Formula that describes the thermal equilibrium of gas electrons and ions as a direct function of variations in temperature.

Piezoelectric motion systems are mechanical systems that utilize piezoelectric materials to generate controlled motion or...

The total luminous flux given out per unit area; i.e., the sum of the luminous emittance and any radiation that is reflected...

A well-corrected flat-field eyepiece with good eye relief. Similar to a Huygenian.

The formula that indicates the total radiation at all wavelengths from a perfect blackbody. W Total = 5.67 x 10-12 T 4(W/cm2)

Histology is the branch of biology and medicine that involves the study of the microscopic structure of tissues and organs...

The line from a spark or other very hot source that has greater intensity than that of a line produced by an arc or flame...

In computer graphics, a character generator that produces alphabetical and numerical characters with some punctuation and...

A ferroelectric polycrystalline ceramic material used in optical memories for computers and as a piezoelectric transducer.

1. The decrease of the absorption (or gain) coefficient of a medium near some transition frequency when the power of the...

A bolometer that serves to record. The photographic record formed by the bolometer may be called bolograph or bologram.

An optical table, also known as an optical bench or an optical breadboard, is a specialized platform used in optics...

A temperature radiator whose spectral emissivity at all wavelengths is in constant ratio (less than unity) to that of a...

A crystalline ferroelectric material used primarily as a substrate and an active medium for thin-film optical modulators and...

In a laser, the fraction of plasma volume used by a particular transverse mode of oscillation, a determinant of the gain...

A position inside a crystal lattice that is not one of the proper lattice sites in the crystal. Impurity ions of the proper...

Separation of incident laser pulses by several seconds so holographic plates can be changed and sandwiched between the...

The area of optics in which the wave nature of a particle is exploited to carry out very accurate interferometry and other...

Spectrum characterized by equal energy (power, flux) per unit wavelength interval.

A laser resonator in which a mode oscillating between the mirrors will converge upon the laser's longitudinal axis.

That branch of astronomy concerned with the study of the moon's physical characteristics.

The base used to hold an astronomical telescope. It may be either altazimuth, with horizontal and vertical axes of rotation,...

The ability of a vision system to interpret an image in a short enough time to keep pace with most operations.

A reticle pattern in a surveying instrument consisting of parallel lines that can be superimposed on a calibrated rod,...

The point on a cutting line that will become the geometrical center of the cut lens.

In a local area network, a unique signal that travels from one node or station to another, providing them serially with...

1. The process of aligning the optical axes of optical systems to the reference mechanical axes or surfaces of an...

A mode of laser printing in which each pixel is printed four times, providing sharper lines and a continuous tone from...

In optical character recognition, the method of dividing a string of characters into separate, distinct characters.

Silicon carbide (SiC) light-emitting diodes (LEDs) are semiconductor devices that emit light when an electric current is...

Change of the spatial distribution of a beam of radiation when it interacts with a surface or a heterogeneous medium, in...

An instrument that is used to detect high-energy particles by the pulse of the current formed when a particle passes through...

A thin-film photoconductive cell that is sensitive to the infrared region. The photosensitive material of the cell is...

An immersion liquid used to treat polarizing filters to eliminate the effects of surface variations and to minimize the...

A system used for measuring direct solar radiation.

A magnetic-deflection mass spectrometer that has an electrostatic field placed perpendicularly to its magnetic field,...

A device used in electron microscopes and particle accelerators to focus electron beams by the arrangement of four...

A method for characterizing a fiber wherein an optical pulse is transmitted through the fiber, and the resulting light...

Phase shift in electromagnetic signals caused by daily variations in the ionosphere, often during sunrise or sunset.

In fiber optics, a material whose properties, usually of transmission, are distinctly affected by the absorption of water...

A diode laser is a type of laser that uses a semiconductor diode as the active medium to generate coherent light....

A microdisplay is a miniature electronic display technology that is designed to project visual information onto a small...

With respect to display systems, a device that uses an independent light source and a control-layer medium, the active...

The transform defining that, if a reference beam is a divergent spherical wavefront, then the reconstructed image will be...

An optical device that permits the alignment of a gun, cannon or rocket launcher system with its target.

Holmium lasers are a type of medical laser that utilizes holmium-doped crystals as the gain medium. The term holmium laser...

A flaw deliberately introduced into an optical fiber to prepare it for cleaving.

A coil used to focus an electron beam by the generation of a magnetic field parallel to the beam.

A gas laser in which the electrodes are mounted perpendicular to the optical resonator.

That voltage required across a Pockels, Kerr or other electro-optic light modulator to retard one polarization electrical...

A dielectric sphere with an index of refraction that varies with distance from the sphere center. A parallel beam of rays is...

The light flash, produced in flash photolysis, that is triggered within a second discharge tube by the third electrode. It...

An electron lens consisting of a homogeneous axial electric field and a magnetic field used in high-quality image tubes for...

A plasma accelerator is a type of particle accelerator that uses electric fields and magnetic fields to accelerate charged...

Remote sensing is a method of data collection and observation where information about objects, areas, or phenomena on...

The frequency band from 3 to 30 kHz. The corresponding wavelengths are from 10 to 100 km. (VLF).

The movement of particulate material by flowing gas or liquid.

A statistical method of dealing with a series of values where each value is squared, the mean of these squares is...

A defect in the cleaved end face of an optical fiber, in the form of a sharp protrusion at the edge of the fiber.

A fiber optic device that uses a HeNe laser, beamsplitter, monochromator and photomultiplier to detect trace levels of...

A visible laser beam generated coaxially with an infrared or other invisible laser beam to aid in its positioning.

A critical image parameter in applications where object position may change dynamically relative to the imager; this is a...

An instrument or system capable of both transmitting and receiving a signal.

Synonym for multimode distortion. Also called mode dispersion.

A change in the refractive index of an optical fiber caused by variation in the length of the fiber core in response to...

A ruggedized scintillation counter used in oil well logging. The cylindrical housing contains a gamma ray source, a...

Quantum-enhanced metrology refers to the use of quantum mechanics principles and techniques to enhance the precision and...

The application of coating without heating of the substrates.

The changing of the kinetic energy of a mobile electron into radiant energy, as in formation of x-rays.

An aperture, usually rectangular in shape, with a large length-to-width ratio, and a fixed or adjustable shape through which...

Refers to the characteristic hue of the ocean according to the presence and concentration of specific minerals or...

The three lines in the spectrum of cadmium that have the purest radiations and that were first used by Michelson to...

An analog signal capable of being modulated as to frequency, amplitude or phase to carry information.

The radio waves of the electromagnetic spectrum that have frequencies of up to 10,000 megacycles per second.

A concave surface that has too much negative power; i.e., its radius of curvature is too short. This condition can be...

A type of fiber optic sensor that detects alteration in position, distance, pressure, liquid level or temperature by...

A flat plate having its surface formed into a random pattern by abrasives. Radiation wavelengths that are longer than the...

A variation from standard physical vapor deposition (PVD) coating techniques, magnetron sputtering is a plasma coating...

A type of fatigue found in optical fibers, caused by water or another corroding agent.

The theoretical explanation and analysis of the interactions between electron waves and crystals used in studying electron...

The ejecting of ions from the surface of a material.

A chemical substance that exhibits fluorescence when excited by ultraviolet radiation, x-rays or an electron beam. The...

In positioning, in-plane rotation about the vertical axis. Also known as azimuth.

A resampling and interpolation method that uses only the value of the nearest neighbor pixel, while not considering values...

The central wavelength range of a transmitter based on the worst-case scenarios of temperature, manufacturing and other...

A wave that is guided by the interface between two different media or by a refractive index gradient in the medium. The...

The higher throughput obtained with an FTIR device compared with traditional spectrometers that need slits to achieve...

A high-speed, narrow-field lens consisting of two achromats spaced about the aperture stop. Its uses include portrait...

An instrument designed to give precise and rapid detection of changes in tumor growth as well as the location of small...

A number that indicates the magnitude of the shift in a solid of positive and negative charges in opposite directions when a...

A method of measuring complex sequential photosynthetic reactions by varying the pulse time and wavelength of light...

The ionization and spark emission due to exposure to ultraviolet radiation.

A defect of a binocular instrument causing two images to be seen separately instead of being fused. It is caused when the...

Specially designed optics for the observation and photographing of hydrogen in a bubble chamber.

The change in the refractive index of a material under the influence of an electrical field.

A type of cooling system in which one fluid is used to carry heat off another without direct contact between the two.

A lens, usually having one or more cylindrical surfaces, used to produce distorted images and later to restore them to true...

The graph of a curve describing the spectral irradiance of extraterrestrial sunlight.

The measurement and analysis of color using a photoelectric instrument having three filters with broad spectrum bands.

Also referred to as the V number in fiber optics; the normalized frequency is a dimensionless quantity, denoted by the...

A type of asynchronous shutter device that is used particularly in CCD sensor applications to capture an image of a...

A well plate, also known as a microplate or microtiter plate, is a flat plate with multiple small wells or depressions...

Gallium arsenide phosphide (GaAsP) is a semiconductor alloy composed of gallium (Ga), arsenic (As), and phosphorus (P). It...

A piece of uniform birefringent material placed at a 45° angle to the plane of polarization in a polarizing microscope...

A method of applying antireflection coatings to optics that avoids the elevated temperatures normally used. A cold coating...

Backscatter refers to the phenomenon in which radiation or waves are scattered backward, opposite to the direction of the...

A ray that travels from one point to another without being reflected or refracted.

Pictorial information processing in which the processed picture shows a family of equidensity lines or bands coded with...

In electrical equipment, power variations that are temporary (as opposed to the permanent, cumulative effects of drift).

The smallest amount of photon energy to pass a detector window and be counted.

In a telephoto lens, the ratio of the overall length to the focal length of the lens. It is generally about 0.8 to 0.9 in...

Concerned with the transmission and reception of both sight and sound. An audiovisual system communicates pictorial images...

A small erect-image telescope for use as a sighting device on a rifle. The chief requirement is a long eye relief to avoid...

A method of determining the abrasion resistance of very hard materials by passing a weighted wiper blade across them in a...

That property of certain optical devices, e.g., a penta prism, that maintains the angular relationship between the entering...

Computer vision enables computers to interpret and make decisions based on visual data, such as images and videos. It...

A character generation CRT that functions on the principle of secondary emission. The target holds a set of aluminum...

A gradual change in the output of a circuit or instrument over time.

The use of head-mounted displays and body-operated remote actuators to control distant machinery. Provides a virtual...

The unit solid angle subtended at the center of a sphere by an area on its surface equivalent to the square of the radius;...

A semiconductor material that is used as an infrared detector for light up to 5 µm in wavelength.

The intermolecular attraction between two surfaces, as between a substrate and a coating; it is an important factor in the...

A characteristic of laser output, calculated by dividing the speed of light by the linewidth of the laser beam. The temporal...

Radiation emitted by electrons when they travel in circular orbits at speeds close to that of light. Synchrotron radiation...

A technique for obtaining improved resolution of images produced by large telescopes and distorted by the effects of...

Device in which contact ionization of atomic particles and thermionic electron emission are used to produce magnetically...

A variation of tomography in which several photographs of a patient are taken at different angles, and back-projection of...

The use of photonic devices rather than electronic devices to make connections within and between integrated circuits.

A waveguide is a physical structure or device that is designed to confine and guide electromagnetic waves, such as radio...

Qualitatively, the inverse of the amount of velocity produced by the application of a sinusoidal force to a system;...

A technique used in astronomy that requires a radio telescope to be directed at a point in the sky west of the object under...

A MEMS fiber optic switch is a microelectromechanical system (MEMS) device designed to selectively route optical signals...

A colorimetric concept related to the apparent visual color of a source (not its temperature). For a blackbody, the color...

The ray of an oblique pencil beam that passes through the center of the pupils. It is the effective axis of the oblique...

A desklike apparatus with an opal glass surface illuminated from beneath by fluorescent tubes. It is equipped with roll...

Frequently used in astronomical measurement, it is based on the diurnal rotation of a star relative to the fixed stellar...

A general-purpose lens, also known as the Celor lens, used widely in photography and commercial processing; it has the form...

The process of heating and slowly cooling a solid material, like glass or metal, to stabilize its thermal, electrical or...

An image-processing device that scans in a straight line parallel to the axis of a rotating cylinder to which the material...

A device that completely or partially restricts the amount of light reaching the eye.

Retroreflection is a phenomenon in optics where light is reflected back toward its source, typically in a direction nearly...

A permanent joint whose purpose is to couple optical power among two or more ports. Also, a device whose purpose is to...

With respect to microscopy, light that is directed down through the objective onto the specimen and then returned by...

In a laser diode, the photocurrent produced by a photodiode that detects the emission from the rear facet of the...

A filter that transmits light in a series of sharp, widely spaced wavelength bands by its sandwich construction of...

Generally, a rotatable table with scales marked in degrees. The fiducial marking also may be a vernier scale. The same...

A type of pyroelectric detector with favorable qualities of linearity, sensitivity and spectral responsivity used in FTIR...

A photodetector composed of a semiconductor material whose responsive properties can be altered by the addition of...

In gradient index optics, a gradient profile in which the refractive index varies symmetrically about a point.

Digital holographic microscopy (DHM) is an advanced imaging technique that combines holography and digital image processing...

A spectral phenomenon in which the degree of the photoresponse of an illuminated semiconductor is determined by the...

Situation in which the observer requires fewer than three independent stimuli to make color matches. Dichromats require only...

An instrument that photographs the spectra of an extraterrestrial object.

The maximum distance at which the eye can perceive and evaluate objects.

Pertaining to the possession of photoelectric characteristics as a result of the properties of the true crystal and not of...

An optical clock is a highly precise and advanced timekeeping device that relies on the oscillations of electromagnetic...

A crude area on the polished surface, produced during coarse grinding, that subsequent fine grinding does not remove, owing,...

In a microscope, the diaphragm located between the Bertrand lens and the eyepiece, which is closed during conoscopic viewing...

The thin edge of a refracting prism; the line of intersection of two refracting surfaces of a prism.

In detectors, the ability to switch on and off electronically, thus producing the effect of a mechanical shutter.

In polarization-preserving optical fibers, the element used to induce birefringence. The SAP is highly doped to provide a...

Low Earth orbit (LEO) refers to a region in space that is relatively close to Earth's surface, typically characterized by...

A television system designed to obtain pictures of objects or scenes beneath the surface of the water. Generally, a...

A laser having a lasing material that is a fluorescing organic dye. Depending on the dye used, it can produce emission in...

Fraction absorption over a specified range of wavelengths.

A thermoplastic or thermosetting material used to hold an object fixed and keep it from deterioration. In microcircuitry,...

The measurement of the ability of matter to absorb, transmit or reflect infrared radiation and the relating of the resultant...

Two lenses, separated by a distance equal to the sum of their focal lengths, and retroreflecting mirror assemblies, one of...

In a lens system, a group of elements considered as an entity; either a front or rear member depending on whether it is...

Basically, a hydrogen atom with two alterations, positronium is the lightest atom in the universe and has an extremely light...

A Pockels cell, also known as an electro-optic modulator, is an optical device used to control the polarization of light by...

The process whereby a spectacle lens is placed in a frame.

Distance between the front vertex of a lens and the object.

A laser, usually employing helium-neon or other gases as the active medium, used for alignment in industrial applications.

The effect produced on a wave frequency because of the relative motion of a source or an observer. The radiation emitted...

A type of paper chromatography that produces a chromatogram that is horizontal instead of vertical.

Property of a surface which, because of directional reflection, is responsible for the degree to which reflected highlights...

Computer hardware or firmware that accesses character patterns stored in read-only memory and displays them at specific...

A device similar to distributed feedback lasers in construction and operation, but in which the period grating that produces...

Totally coherent radiation is produced by a purely monochromatic point source. In the real world the energy will have a...

An instrument that spectrally analyzes the flux reflected from a material. The reflected flux may be total, diffuse or...

A surface heat-treating process that produces a highly stressed surface. In case-hardening of glass, a plate of glass is...

Optical glasses containing the oxides of rare earths such as lanthanum to impart a very high refractive index combined with...

A thermal source that emits less radiation than a blackbody under identical temperature conditions.

A wireless stereo imaging device used in conjunction with a monitor to produce a virtual interactive environment. Liquid...

Radiant flux incident per unit area of a surface. Also called radiant flux density.

The measurement of heat energy as determined from absolute zero as the zero point on the scale. Increments are identical to...

CoaXPress (CoaXPress or CXP) is a standardized digital interface and communication protocol used primarily in machine vision...

A system of elements which rotates the optical image with respect to the optical axis by a factor of pi radians.

The visual perception of motion when fixed stimuli are exposed in rapid temporal and spatial succession.

A term denoting the magnitude and direction of the magnetic field associated with an electromagnetic wave when describing...

In rangefinders and height finders, a rotatable or sliding wedge-shaped element used to divert the line of sight precisely...

A type of compensator for use with a microscope and consisting of a quarter-wave plate in a fixed position and a rotatable...

A product of the area of a light beam (normal to its direction of propagation) and the solid angle that the beam includes;...

A method of reducing dark current in charge-coupled devices by holding all the clocks at negative voltage during the...

A far-field pattern holographically reproduced image that is categorically considered with three-dimensional lensless...

Anisotropy refers to the property of exhibiting different values or characteristics when measured in different directions....

A lens system made up of two sets of similar lenses, each of which compensates for many of the aberrations produced by the...

Laser-powered telephone device for analog communications that employs a vibrating plastic membrane as a transmitter to...

Freeform mirrors refer to reflective optical components that deviate from traditional symmetric or rotationally symmetric...

A cathode-ray tube that increases the brightness or size of an image or forms a visible image from invisible radiation. The...

A technique used to suppress extreme noise amplification during digital image reconstruction that relies on smoothing and...

An OLED display formed by creating an array of OLED pixels connected by intersecting anode and cathode conductors arranged...

Also referred to as the axial ray (or a-ray), a marginal ray originates from the axial point of the object and passes...

Embedded vision refers to the integration of computer vision technologies into various embedded systems, devices, or...

Collisional absorption of energy that occurs in inertial confinement fusion systems when hydrodynamic expansion of the...

A maser that relies on the fact that electrons in orbital motion in high-magnetic fields will emit energy at the cyclotron...

A pattern on an oscilloscope display that consists of a string of shapes that resemble eyes. Because the pattern becomes...

A source that attempts to create the characteristics of an ideal blackbody. It consists of a cavity, generally spherical,...

The distance, on either side of the object plane focused on, through which satisfactory image definition can be obtained....

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...

A scanning electron microscope (SEM) is a powerful imaging instrument used in scientific research, materials...

A gas lamp used in the early 1900s as a physical standard for measurement of luminous intensity. The Hefner unit was...

Characteristic of an absorber in the IR region, whereby absorption increases as a direct function of the intensity of the...

A write-once optical disc storage system in which the optical head reads continuously while writing to check the accuracy of...

A transmission electron microscope (TEM) is a powerful microscopy technique that uses a beam of electrons to create...

A type of fiber optic cable that emits light from its sides along its length.

A film or plate that is usually coated on both sides with a very fast emulsion that is sensitive to x-rays, and used to...

Photoplethysmography (PPG) is a non-invasive optical technique used to detect changes in blood volume in tissues. It...

The conductivity increase exhibited by some nonmetallic materials, resulting from the free carriers generated when photon...

A high-frequency pulse-rate laser with an output limited by the heat capacity of the laser medium. Instead of having...

An otoscope is a medical device used by healthcare professionals, particularly ear, nose, and throat (ENT) specialists,...

An astronomical scanning technique for capturing images of stars without moving the sensor. To perform a drift scan, a CCD...

In an optical system, noise created by mode-dependent optical losses and variations in the distribution of radiant power...

A mixed-signal oscilloscope (MSO) is a type of electronic test instrument that combines the capabilities of both a...

An SI prefix meaning one billionth (10-9). Nano can also be used to indicate the study of atoms, molecules and other...

Color sensitivity extended to cover the entire visible spectrum out to the red.

The amount of x-rays used to penetrate and diffuse a target sample undergoing electron-probe microanalysis.

A device that combines the functions of encoder and decoder.

An adhesive used to hold optical elements to blocking tools. It is usually a thermoplastic substance such as resin, beeswax,...

The formation of a distinct, irregular surface pattern on a photographic emulsion due to differential swelling of the...

The use of miniature scanners to project raster-scanned video images directly onto the surface of the human retina,...

The axes of symmetry in a crystal structure. See also biaxial crystal; uniaxial crystal.

The variation of the electronically detected signal with respect to the scaled version of the classical optical signal...

Successive layering of resistive, dielectric and conductive inks on a substrate by a type of screening process.

A device used to alter the shape of or energy distribution within a beam of radiation.

A piece of glass, pyrex or quartz having one or both surfaces carefully ground and polished plano, generally flat to less...

Piezoresistance is a phenomenon in materials science and physics where the electrical resistance of a material changes in...

The electrical distribution that serves to influence an electron beam in the same way that an optical lens affects a light...

A fast-action shutter inserted between one end of a laser rod and the end mirror; when inserted to prevent emission and then...

A slight displacement in the position of a spectral line because of an alteration in frequency, as a result, in turn, of a...

The departure of a curved surface from the plane that is tangent to its vertex. See sag.

An optical interference coating, vacuum-deposited on a circular substrate, whose transmission characteristics may be varied...

A copolymer of styrene and acrylic used in molded optical components; it has a high refractive index and a low coefficient...

An instrument designed to measure the numerical aperture of an objective.

The second adjustable iris diaphragm in an optical system. In the common microscope condenser system, it usually is located...

In a cathode-ray tube, the deflection of the beam of the tube over an angle that surpasses the angle that subtends the...

An image processing device that displays pseudocolor images by assigning colors to the gray scales according to look-up...

1. A measure of absorbed dose, equal to the energy imparted by ionizing radiation to a mass of matter corresponding to 1 J...

The simultaneous exposure of two holographic plates with emulsions facing the object. After deformation, a second pair of...

The ratio of the radiant flux emitted by a source to the power supplied.

The optical Fourier transform is a mathematical operation applied to optical signals that involves transforming a spatial...

Image processing peripheral that converts video images from cameras into digital format and transfers these digital images...

A measurement technique used for the rapid quantitative evaluation of surface quality based on the detection and analysis of...

The nonthermal conversion of electrical energy into light in a liquid or solid substance. The photon emission resulting from...

A pathogen is a biological agent, such as a virus, bacterium, fungus, protozoan, or parasite, that causes disease in its...

Chemical vapor deposition (CVD) equipment refers to a class of specialized apparatus used in the process of chemical vapor...

A compact optical projection system, mounted on or built into a helmet, and used to project data or a scene directly into...

A test method for determining high-reflectivity levels by monitoring cavity decay within a resonant cavity formed by two...

On a test chart, the pattern designed to direct and measure geometric distortion.

A crystal that may serve as a diffraction grating if mounted effectively.

An image whose left side appears to be the right side, and vice versa.

Transmittance of a solution, or internal transmittance of a transparent solid, is an exponential function of the thickness...

An atmospheric nonlinear process unique to CO2 laser wavelengths, whereby CO2 absorbs 10.6-µm radiation and the CO2...

A small television monitor that replaces the reflex viewfinder in a television camera.

Photoconductivity due to the addition of impurities or external causes.

The spontaneous emittance of electromagnetic radiation by the nucleus of certain radioactive elements during their quantum...

A lens having each of its outer faces curved outward.

Correction of an optical system at four separate wavelengths. This correction, longitudinal and lateral, is possible with...

A Pockels cell in which electrical current is applied in a direction orthogonally to that of the light beam.

The loss of optical power in an optical fiber because radiation escapes through its bends. The radiation loss caused by...

The introduction of a filter into an imaging system to implement a phase contrast for an intensity mapping of a pure phase...

An optical system that is designed to produce a high temperature in a specified area by the optical direction and...

A group of energy levels to which ions in the ground state are initially excited when pumping radiation is applied to a...

Laser ablation is a process that involves the removal or erosion of material from a target surface using laser energy. This...

The entrance slit, also known simply as the slit, is an essential component in optical instruments such as spectrometers and...

Adhering material used to glue optical components that transmit in the infrared. It is easily dissolved by acetone.

A direct recording photometer that is designed to scan a photographic negative to determine its points of isodensity.

Light perceived as achromatic, that is, without hue.

A filter that polarizes light passing through it. It is possible to fabricate sheets of plastic or gelatin that contain...

An optical data storage device that permits the user to store data (write) and play it back (read), but not to erase or...

An efficient, readily soluble blue-green laser dye.

A type of color-generating cathode-ray tube that uses a shadow mask, a thin perforated electrode, located close to the...

In a communications network, a point at which data are received or from which they are sent. Though the term often is used...

A technique for measuring the concentration of any gases. Identical infrared beams are alternately chopped, one passing...

The series of processes used to identify and evaluate crystal structure by using crystalline solids to diffract x-rays. In...

A polishing machine with a lens mounted on a wooden stick, allowing a very wide sweep. It is used to polish hemispherical or...

A characterization of the throughput performance of data storage systems; the EDR is the total of data retrieved divided by...

Simulation of radiative transfer in which each photon is generated by a source and its path through the medium is...

A soft, malleable, stable rare-earth element. Holmium laser systems are used in surgical procedures involving the cutting...

Recombinase polymerase amplification (RPA) is a molecular biology technique used to rapidly amplify specific DNA or RNA...

A standard of luminous intensity evaluated as the luminous intensity of 1 cm2 of a blackbody at the melting point of...

A photonic crystal that comprises magneto-optical material such that the optical response of the device depends on the...

The photographic recording, and later enlarging, of very thin specimens, using an electron beam to form the image.

The unusual and anisotropic diamagnetic quality observed in particular crystals such as those composed of bismuth.

A photometer that uses a photoemissive tube to detect and measure light. See photoelectric photometry.

An instrument for measuring the brightness (luminance) of a scene. It may be a spot meter, covering an area of a degree or...

Glass containing small quantities of neodymium oxide that is used as a filter plate in color television or as a lasing...

The process of grinding the toric surface of a single vision sphero-cylindrical lens.

A center-opening shutter made up of several identical leaves that are mounted symmetrically around the optical axis of the...

The technique of generating ultrashort -- down to subpicosecond -- pulses by pumping a dye laser with mode-locked laser...

A refractometer that has a greater resolving power than a standard refractometer, and that uses a pentagonal prism to split...

1. The anode or anticathode of an x-ray tube that emits x-rays when bombarded by electrons. 2. The screen in a television...

A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of...

A representation of the shape of a surface, including any roughness or other irregularities. The profile can be generated by...

A microlens array is a grid-like structure composed of numerous small lenses, typically arranged in a regular pattern. Each...

An optical projection device designed to project positive color transparencies onto a screen for viewing.

Method for reducing laser speckle in which the object field comes from a real diffuse object or the reconstructed object...

An instrument used to record infrared images of large areas. The recorded data are used to produce maps in false color...

An instrument for measuring reflectance.

A parabolic, elliptical, hyperbolic or circular section created when a solid cone is intersected by a plane.

A device used to count objects that pass a given point by allowing each object to obstruct a beam of light falling on a...

The mechanical structure that holds a number of individual lens elements.

An interferometer that uses a laser as its light source. The purely monochromatic nature of the laser results in improved...

A laser that relies on chemical activity instead of electrical energy to produce the pumping action necessary to form pulses...

An accurate metal prism or plane parallel plate that is cemented to an optical element and remains with it during a series...

A type of laser pulsing with high laser power at the beginning of the pulse.

A lens system that is capable of producing a 360° image, or one that is very close to that. In recording, the image may...

A device for which the output electric field is linearly proportional to the input electric field, and no new wavelengths or...

A small convergent lens, located between the objective and eyepiece of a microscope, that focuses an image of the upper...

In reference to infrared, emissions that are like radio waves but that have a higher frequency.

A laser diode in which the beam is confined to the region of the active layer with gain high enough to accomplish such...

A spectrophotometer in which the beam emitted by the radiation source is split into beams that travel through the sample and...

A device used to measure the intensity of radiant energy.

A photographic camera and processing system used to form a usable record of the subject in a short time, usually a few...

Expression of the nondimensional coefficient of the heat transfer in a convection process.

The physical adaption of the eye lens, by means of ciliary muscle contraction, in order to maintain a clear, in focus image...

A point source of light used for the test and evaluation of image quality. May be a backlit pinhole in an otherwise opaque...

Use of a laser to solder joints by melting the solder coatings on the mating components.

The mounting of a concave diffraction grating and a plate holder at the ends of a rigid bar. The ends follow separate...

The difference in angular bearing of an object as seen by the two eyes, due to the separation of the visual optical axes.

In image processing, the location of edges by employing templates that respond to the first or second derivative of...

A device that converts stored electrical energy into light by means of a sudden electrical discharge.

The number of fields scanned per second in a television system. The US standard is 60. Also called field frequency.

Optical fiber with a large core, often a step-index fiber; "large'' is at times defined as greater than 85 µm.

A lamp that uses the transmission of an electric current through a gas or vapor to produce illumination. Neon, mercury and...

A sequential scanning device, utilizing a revolving lens, in which the cathode-ray tube image is transformed into a circle...

A dielectric ceramic material used in laser capillary tubes because of its high electrical resistivity and high thermal...

An instrument designed to measure the refractive power and range of accommodation of the eye. See ophthalmic instruments.

A grating beamsplitter is an optical device that utilizes the principles of diffraction to split a beam of light into...

The highest frequency at which a laser diode can be driven and still be modulated acceptably that further results in the...

A set of rays through a lens originating at a common point and contained in one plane.

A camera equipped with a lens and a long length of perforated film, the latter being moved intermittently between exposures...

A microscope that can be used to observe and magnify microscope specimens while they are being centrifuged. The objective...

Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In...

Dispersion refers to the phenomenon where different wavelengths (colors) of light travel at different speeds when passing...

Coherent source used for analysis of excited state species.

A term referring to the pre-exposed hologram of the subject used in holographic interferometry.

1. An optical distance finder that depends on triangulation of two convergent beams on an object from disparate view points....

Time rate of flow of energy; the radiant or luminous power in a beam.

The effect that the optical losses in a medium can grow when the medium is irradiated with light at certain wavelengths.

A system in which a sequence of direct measurements of the target position is fed into a tracking filter that may produce...

The analysis of the atomic structure of a sample by means of a source radiation that is absorbed and emitted by the sample...

An instrument that divides a single laser beam in two and uses one half as a sensing beam and the other as a reference beam,...

Ellipsometry is an optical technique used to characterize the properties of thin films and surfaces. It is based on the...

The simplest, most inexpensive type of camera, which is shaped as an oblong or square box, containing the simplest lens,...

The photographic filming of the action of x-ray images recorded on a fluorescent screen by means of large lens apertures and...

The finite amount of electrical charge generated in response to incident radiation and transferred from one storage element...

In an optical system having astigmatism, the distance between the tangential and sagittal image planes.

The term quantum refers to the fundamental unit or discrete amount of a physical quantity involved in interactions at the...

A thermosetting material used in the jacket of fiber optic cables.

An absorbing coating medium between fibers, used in some fused fiber optic plates to absorb unwanted light. Such coatings...

Autofluorescence refers to the natural emission of fluorescence exhibited by certain biological structures or molecules when...

The amount of time needed for a detector signal or electronic circuit to reach 63 percent of its final value after a fixed...

A combination of components arranged so as to perform at least one function.

A term used to describe a spectacle lens or blank with one surface totally finished.

The capacity of a chiral substance such as a crystal or molecule to rotate the plane of polarized light that is transmitted...

An instrument used to measure the duration of fluorescence emanating from a biological sample to monitor and evaluate its...

A bundle of filaments of optical glass or other transparent materials that transmit only light, not optical images. The...

Small clefts or fissures that penetrate the glass surface in the form of short-hooked crescents. Fire cracks result from a...

An optically bistable device used for photonic switching, constructed of a multiple quantum well biased by an external...

Fiber optic cable in which the arrangement of fibers within the bundle has been made random so that output light will be...

A passive coupler that distributes signals from one or several inputs among a larger number of output waveguides arranged...

The absorption of a material by a medium or system that has formerly been released from absorption by that same medium or...

The ray that passes through the center of the aperture stop in an optical system. It often is called the principal ray of an...

The reflection that occurs within a substance because the angle of incidence of light striking the boundary surface is in...

A laser that emits radiation continuously rather than in short bursts, as in a pulsed laser.

In image processing, the memory that stores the values for the point processes. Input pixel values are those for the...

An accurately produced hole of any size and shape that is used as a masking device in an optical system. Pinhole apertures...

Birefringence of materials that is induced or altered by stress fields.

An optical tooling instrument consisting of an objective lens, a focusing lens, an optical micrometer, a reticle and an...

The site behind the lens system in a camera where photographic media are positioned for exposure.

An absorption peak refers to a sharp increase or spike in the absorption of electromagnetic radiation at a particular...

The broadening of spectral lines due to the collision of radiating particles with one another and the resulting interruption...

An optical wedge of very small angles that admits light while sealing out moisture and dirt and that may be rotated to...

See periscopic lens; rapid rectilinear lens.

A gas laser wherein the gas mixture is not exhausted into the atmosphere but is continually recycled. It is excited in the...

E.I. duPont's trade name for a material used in the jacket of fiber optic cables. It is flame-retardant, thermally stable...

An objective measure of an object's brightness that is derived from the ratio of the luminance of its lightest section to...

A measure of the closeness with which an optical image is capable of resembling the original object. The factors that affect...

A prism formed by dividing a Nicol prism in a plane parallel to the path of vibration of the transmitted light and taking...

A type of mirage that creates a distorted vertical image of relatively flat objects so that they appear as mountains,...

An electrical problem that occurs when voltage is not the same with respect to ground at every node of a system, causing...

The optical element that receives light from the object and forms the first or primary image in telescopes and microscopes....

Liquid crystal on silicon (LCoS) is a display technology that combines liquid crystal materials with silicon-based...

In physics, the law of reversibility is often associated with the concept of reversibility in thermodynamics. The law...

A measure of the optical path length for light traveling from the sun or other celestial source through Earth's atmosphere...

Operation in which the dispersion of a pulse limits the distance between repeaters in optical systems. Waveguide and...

A camera equipped with angular scales in altitude and azimuth. The scale readings are imprinted on the film when an exposure...

The fundamental tool of microdensitometry, the microdensitometer is an instrument used for the precise measurement of...

A disc whose surface contains recorded digital data at high-packing densities arranged in concentric rings. The data,...

Of or pertaining to the methods of the French philosopher Rene Descartes. Refers to the standard orthogonal X-Y-Z coordinate...

Mode-locking is a technique used in lasers to produce ultrashort pulses of light with durations on the order of picoseconds,...

A measure of the sensitivity of a detector; the reciprocal of noise equivalent power (NEP). See D*.

A substance that increases a material's sensitivity to electromagnetic irradiation. In photodynamic therapy, a drug used to...

The light formed by visible radiation that, in traveling from light source to object, undergoes one or more reflections. In...

Also known as constant angle or constant deviation fringes. The interference fringes observed with dense flat plates near...

A piezoelectric transducer made of a thin strip of piezoelectric material bonded to a strip of metal.

The individual coherent series of lightwaves that defines a quantum of radiant energy. Light quantum is equal to hv, h being...

A transparent crystalline substance in which the refractive index of the optic axis (extraordinary axis) is different from...

Refers to a notation system using a base of 3 and the numerical characters 0, 1 and 2.

To control, by magnifying or reducing, the size of a televised image, either electronically or optically.

An optical instrument containing a gimballed sighting telescope, used to measure angular relationships in horizontal and...

A formulaic description of the linear change of the reciprocal optical dielectric tensor with either stress or strain.

A plane-parallel interferometer that yields extremely high contrast over a wide range of finesse values without...

That portion of the telecommunications network that runs from a local central telephone to the subscriber premises.

A circular optical wedge (prism of small refracting angle) mounted to be rotated in the path of light rays to divert the...

An electron tube having two electron guns, one on each side of the storage medium, to encode the information onto the...

A constant equal to the universal gas constant divided by the Avogadro number. It is approximately equal to 1.38 x 10-23 J/K...

A flowmeter is a device used to measure the flow rate or quantity of a fluid passing through a particular point in a system....

The observation and measurement of the flatness of a mirror surface by contacting an optical flat with the mirror. The...

A halogen lamp, also known as a tungsten halogen, quartz-halogen, or quartz iodine lamp, is an incandescent lamp that uses a...

The addition to the information signal in communications of redundant bits that enable the originally encoded message to be...

Capable of transmitting light with little absorption and no appreciable scattering or diffusion.

Single wavelength source with a larger linewidth often containing multiple longitudinal modes.

Optical tweezers refer to a scientific instrument that uses the pressure of laser light to trap and manipulate microscopic...

In a series of amplifiers, amplification by each of the preceding output.

A Bose-Einstein condensate (BEC) is a state of matter that forms at temperatures close to absolute zero. It is named after...

A polariton is a quasiparticle resulting from the strong coupling between photons (light particles) and certain types of...

The effect whereby a light beam is deflected by a birefringent prism when its polarization is changed by voltage applied to...

Having the characteristics of glass.

A photomask, also known simply as a mask or reticle, is a key component in the photolithography process used in...

A wide-field camera based on the classic Schmidt optical system used to photograph Earth-orbiting satellites.

A device used for measuring the height of clouds from a position on the ground. Measurement technique uses a vertically...

Chip-on-board (COB) lights refer to a type of LED lighting technology where multiple LED chips are directly mounted onto a...

A series of flanges or other conducting surfaces, usually metal, attached to an electronic device to transmit and dissipate...

In dry etching, a method of characterizing the composition of solid materials such as metal. Atoms in the OES technique are...

A camera with a very high aperture lens or mirror system for photographing x-ray fluorescent screen images, mainly to save...

A material often used in the construction of optical instruments because of its low coefficient of thermal expansion (0.9 x...

A blank area (caused by insufficient inking of the paper) that falls within the range of an intended character stroke in an...

The first-order spectrum formed by a diffraction grating.

An obsolete term once used to describe a unit of radiation dosage.

A thermal infrared imaging procedure developed for quality control of printed circuit boards. The thermogram of each board...

In sensitometric testing, a series of areas progressing by equal density steps (usually the increments between steps are...

A technique used in photolithography of computer chips to compensate for errors caused by the proximity effect, which...

SI unit of luminous incidence or illuminance, equal to 1 lumen per square meter.

A camera system used for microphotography in which the document to be recorded is on a flat bed, perpendicular to the lens...

The organ of vision or light sensitivity.

The angular difference in the direction of an object as seen from two points of observation. The angle subtended at the...

In multifocal spectacles, a term used to denote glass with a high refractive index that has been fused to the blank and...

Sometimes referred to as the surface normal or 'surface norm'; the normal is an axis that forms right angles with a surface...

The transition boundary between P-type and N-type materials in a semiconductor.

Photolithography is a key process in the manufacturing of semiconductor devices, integrated circuits, and...

A device used to view microfilmed documents where the image on film is projected, in magnified form, onto a rear projection...

For a laser, the maximum exposure time that the laser design allows; 0.25 seconds for a Class 2 laser.

The value equal to the raster height divided by the half-period of a periodic test pattern.

Reciprocal of the dispersive power of an optical material. See Abbe constant.

A filter that allows heat radiation from an incident beam to pass without absorption or reflection.

The recording achieved when a surface, illuminated by a signal-controlled light beam, emits electrons or reacts in some...

Hydrophobic is a term used to describe substances or materials that repel or do not readily interact with water. The word...

Array used in coded-aperture imaging experiments with two-beam CO2 lasers that provide an artifact-free process, faithful...

A material or system that emits x-rays.

Transparent glassy and or crystalline structured materials engineered from inorganic, non-metallic materials via various...

Measures by heterodyning interferometry the local slope of a vibrating sample. The method allows the reconstruction of a...

The total optical power loss in a system. The loss budget is often stated in terms of the transmitted power and the power...

An instrument used for video or computer data storage in which a laser optical head is used to write digital information...

A model that predicts laser-induced damage to thin films caused by irradiation of identical, randomly distributed film...

An impurity in a material that is capable of inducing electrical conduction in that material by transferring an electron to...

In optics, the term denoting the lack of a fixed phase relationship between two waves. If two incoherent waves are...

An event-based image sensor, also known as a dynamic vision sensor (DVS), is a type of digital imaging device designed to...

Ratio of the molecular diffusion coefficients of momentum in terms of heat; used in convection studies.

A loss of resolution or detail in a television signal caused by the size of the electron scanning beam.

The manifestation of light from scatterers outside the plane of the object in coherent light systems. The output of these...

The grinding and polishing of rock samples, to a thickness of less than 0.05 mm, for study with petrographic microscopes....

A ring laser gyroscope (RLG) is a type of gyroscope that uses laser light to detect and measure changes in orientation. It...

A Cassegrain telescope having a parabolic primary mirror, a spherical secondary mirror and a zero-power doublet in the...

A solid with a structure that exhibits a basically symmetrical and geometrical arrangement. A crystal may already possess...

A photometric instrument used to measure the illumination falling on a surface. It may be photoelectric or visual.

Calculation of gas and aerosol transmission and emission characteristics for several model atmospheres, including two model...

The determination of the degree to which a manufactured component can deviate from its ideal specifications of material and...

Germanium crystal refers to a crystalline form of the element germanium (Ge), which is a metalloid and semiconductor...

The lowest excitation power level at which a laser's output is mainly the result of stimulated emission rather than...

A device used for the comparison of spectra used, in turn, for the comparison of elements, such as the absorption lines in...

The technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon. The...

A blank to which a piece of glass of a different refractive index will be fused to form a multifocal lens.

A device used for coding messages and having a fiber bundle that is aligned at both ends and scrambled in the middle, potted...

A line passing through the center of a lens surface, from edge to edge.

A device (e.g., prisms, lenses, tubes) used to align a beam in a system.

A pulsed dye laser in which the excitation is provided by means of a flashlamp. Output is tunable from 335 to 850 nm, with...

An optical instrument designed to permit the visual examination of the interior of the bronchi.

An instrument consisting essentially of a tube 160 mm long, with an objective lens at the distant end and an eyepiece at the...

An image intensifier, also known as an image intensification tube or image intensification device, is a specialized...

A neuromorphic vision sensor is a type of imaging device designed to mimic the structure and functioning of the human visual...

the photography of very close, and typically small objects with a magnification of approximately 1:1

Inquiry made to gain access by a master station in a token ring network.

In biology, particularly genetics and evolutionary biology, the phenotype refers to the observable characteristics or traits...

A rotating plate containing two or more lenses to provide a rapid interchange.

In television, the period during which the electron beam is cut off while the raster returns from the right-hand side of the...

A type of laser spectroscopy used to measure short-lived isotopes by observing sudden bursts of fluorescence resulting from...

In morphological image processing, a series of dilations followed by the same number of erosions.

The frequency band from 30 to 300 MHz. The corresponding wavelengths are from 1 to 10 m. (VHF).

An aspheric plate placed at, or near, the center of curvature of a spherical reflector and used to correct for spherical...

A special form of microscope that utilizes interference for observing and measuring the phase and optical thickness in...

A measure of the transmittance through an optical medium. Optical density equals the log to the base 10 of the reciprocal of...

A spectrograph used to detect radiation in the range of the ultraviolet in the electromagnetic spectrum. It is made up of...

Commission Internationale de l'Eclairage, the international commission on illumination.

An analytical technique used to determine, identify and localize impending malfunctions. It is based upon quantitative and...

An optical device capable of transforming unpolarized or natural light into polarized light, usually by selective...

The conduction of electricity in a gas as a result of the ions generated by collisions between electrons and gas molecules.

Instruments used by ophthalmologists and optometrists to study the eye. There are, for instance, the ophthalmoscope to...

The transparent component of an optical reader that transmits the image rays of the characters to be read.

An image tube that functions in low-light-level conditions by virtue of its series of stacked sections wherein the output of...

A device that changes the number of lines per frame of a video image to adapt to a lower resolution format, either by...

A fluorographic method whereby the sensitive photographic medium is pressed against a fluorescent screen to form a visible...

The degree to which a pair of fine lines can be aligned to each other. A normal observer will demonstrate an accuracy of 10...

In the context of electronics and semiconductor manufacturing, a wafer refers to a thin, flat disk or substrate made of a...

A filter, used in photography, that absorbs the ultraviolet and extreme blue violet radiation scattered by atmospheric haze.

Flux per unit solid angle and per unit area measured normal to the direction of propagation of the flux.

A pixel-based computer graphics system that simulates the tools of an artist.

The use of photographic recording equipment to measure radiant energy. With this procedure, many measurements of radiant...

The emission of gas or de-aeration due to thermal variations and often occurring in a vacuum. In a cleanroom, contamination...

Formulaic compensation to correct laser ranging data for the effects of horizontal refractivity gradients; it requires the...

The monochromatic transparency effect produced by the immersion of a finely powdered substance (e.g., glass or quartz) into...

A term used to describe a photograph, film or television picture where the values for black and white areas are at or near...

The combination of more than one type of small-molecule monomer into a polymer.

Device which determines particle velocity through the measurement of scattered interference of a beam pair from a single...

In a birefringent material, the index of refraction varies with the direction of vibration of a lightwave. That direction...

A narrow linewidth optically transmissive or reflective component intended for use with a highly monochromatic or single...

A precision lens designed to convert the plane wavefront output of an interferometer to a spherical wavefront for the...

Optical elements that use diffraction to control wavefronts. Diffractive optical elements include diffraction gratings,...

A naturally occurring pigment in tissue that may selectively absorb certain wavelengths and can be used to aid in targeting...

Two flat parallel electrodes that are vertically mounted alongside each other in a cathode-ray tube and produce horizontal...

Use of a photoelectric receiver to sense an object's presence by detecting a small amount of the emitter's light that is...

Photodynamic inactivation (PDI) is a therapeutic approach that utilizes the combination of light, a photosensitizer, and...

That radiation characterized by wavelengths ranging from 0.2 to 0.3 µm in the electromagnetic spectrum.

A method for obtaining the optical absorption spectra of solids, semisolids, liquids and gases. PAS is inherently...

A filter that is transparent to longer wavelengths but opaque to shorter wavelengths.

The analysis of structural and molecular dynamics caused by low temperature.

An instrument designed to measure the index of refraction of a gas by the interference patterns formed by two beams, one of...

A detector cooling device in which a gas under high pressure escapes through an expansion valve in the tank; as the escaped...

A statistical analysis of facts obtained when the intensity of x-ray diffraction is calculated at different angles. In this...

In spectacle lenses, the lateral measurement of a multifocal segment at its maximum width.

One of the two principal types of optical glass, the other being flint glass. Crown glass is harder than flint glass, and...

The fiber optic connector developed and manufactured by Amphenol Fiber Optic Products.

Fraction of light counter propagating collinear with the incident source. Processes considering backscattering are Raman,...

A laser having a rare-earth chelate within a plastic host as the lasing material. The chelate laser is easily pumped and has...

Degradation factor in coherent light systems where the amplitude of the recorded signal is decreased as the number of object...

An image intensifier tube in which the photocathode and the output of the microchannel plate are proximity-focused on the...

A measure of the total light passed by a shutter during an exposure, compared with the light that could be passed by an...

The successive analysis or synthesizing of the light values or other similar characteristics of the components of a picture...

Diffraction efficiency is a measure of how effectively a diffractive optical element (DOE) or diffraction grating directs...

In optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it....

A high-quality, narrow-angle lens of high aperture designed for low magnification in the recording of cathode-ray tube...

Activity of a radionuclide having one spontaneous nuclear transition per second.

Device which measures the index of refraction of glass as well as the dispersion over visible range.

A fiber-coupled photoconductive antenna (FCPA) is a type of optoelectronic device that combines a photoconductive antenna...

In surface height measurement of optics with steep slopes, the use of two short visible wavelengths to synthesize a longer,...

An optical fiber with a hollow core filled with a liquid material that has a higher refractive index than the solid...

Combining light beams, usually of unlike frequencies, to form a single beam with a frequency that is equal to the frequency...

Atmospheric aberration caused by the Earth's rotation; the degree varies from 0 at the poles to a maximum of 0.31 s of arc...

An alexandrite laser is a solid-state laser that utilizes a synthetic crystal made from the rare earth element alexandrite...

Pertaining to electromagnetic radiation as perceived by the eye; that is, with the contributions as wavelengths in the...

A camera tube widely used in television broadcasting. It consists of three sections within a single vacuum envelope. 1. A...

Unit of measurement of brightness (luminance) equal to one candela per square meter.

An aspheric lens is a type of lens whose surface profiles deviate from the traditional spherical shape. Unlike spherical...

High power laser ablation device that by pulsed operation produces holes of controllable dimension on the scale of microns....

A two-mirror corrector for a parabolic primary mirror that provides anastigmatic performance for large astronomical...

A surgical procedure for correcting vision by reshaping the outer surface of the cornea through the use of a laser system.

A lens used in the optical testing of an aspheric surface. It converts a spherical wavefront into one that precisely matches...

In fiber optic communications, a light source whose beam can be modulated and sent along an optical fiber, and the...

Geometrical partition possible with a sphere that can be four, six, eight, 12 or 20 solid-angle wedges. Each platonic mass...

An alteration in magnification from the center of the field to any point in the field, measured in a radial direction from...

A lamp, usually incandescent, that has a very compact filament, permitting a greater concentration of emitted light, aided...

A scientific CMOS (complementary metal-oxide-semiconductor) camera is a type of digital camera specifically designed for...

An electromagnetic wave lying within the region of the frequency spectrum that is between about 1000 MHz (1 GHz) and 100,000...

A negative powered lens with one surface convex and the other concave, the latter having the greater curvature. It also is...

A spectral line of an internal standard; used to compare radiant energy of the line being analyzed.

A polarizer that consists of dichroic polarizing material embedded in a plastic sheet, and that transmits light that is...

Also known as cathode rays. Formerly, this term described a stream of electrons emitted from the cathode of a gas-discharge...

A facility designed for the observation and recording of astronomical phenomena.

A multiple-beam interferometer, usually consisting of two flat plates, with high reflective ability. The plates are set...

A crystal diode whose rectifying activity is determined by the touching of the crystal to a finely pointed wire surrounded...

A particle that will not normally diffuse through animal or vegetable membrane. Larger than most inorganic compounds,...

Multiple, interconnected circuit elements, contained on or in a common substrate, that function as a unit and not separately.

The differential luminance threshold divided by the luminance.

The average luminous intensity of a point light source measured over all directions.

Ratiometry is a technique used in various scientific fields, particularly in analytical chemistry and biochemistry, to...

The distance between the last vertex of a lens and the image.

The formation of a fan of light or energy rays in a beam as the beam passes through an extremely narrow aperture.

A type of glass optical fiber that provides low pulse dispersion over a broad portion of the light spectrum and as a result...

The unchanging nature of spectral reflectance as vegetational density increases to the point where additional increases in...

A rotating disc that holds several lenses of differing focal length about a diameter. Used to switch lenses in a system...

An optical system that is corrected for distortion and spherical aberration and therefore forms the image of a straight line...

Lens which, by altering the phase, efficiently images through a holographic process.

A salt of formic acid that can be used to enhance the photosensitivity of silver halide crystals.

A form of liquid crystal widely used in displays, achieved by sandwiching a liquid crystal material between two substrates...

A method of analysis in which a pulsed laser beam is used to heat a particle, producing a plasma, or laser spark. As the...

A linear positioning stage, also known as a linear stage or translation stage, is a precision mechanical device used to...

The parameters, relative to polarized light and the Poincaré sphere, that are usually represented as: I, the intensity of...

The figure of merit of a resonator, defined as (2p) x (average energy stored in the resonator)/(energy dissipated per...

A layer between the corona and the photosphere of the sun; its emission is overwhelmed by light emitted by the underlying,...

A technique used to create an achromatic phase shift based on the principle of geometric phase. The phase shift is...

A reference incandescent light source having a luminous intensity that is used in photometry for comparison of other light...

A visual spectrophotometer with a rhomb located directly before the entrance aperture of a constant-deviation...

The size of the field of view in the object space of an optical system as differentiated from that in the image space...

A hologram imprinted on plastic or another medium; e.g., those commonly found on credit cards.

A technique used in holography that involves the mixing of lasers of different wavelengths to produce a beam of shorter...

A type of internal focusing in which only the lens elements closest to the rear of the lens barrel are moved.

Made up of three components; for instance yttrium, aluminum and garnet (YAG).

The penetrating capacity of x-rays that is an inverse function of the wavelength.

An electronic device used to encode video and audio signals of a television camera into radio waves that are broadcast to...

A device containing two opposed quartz wedges of equal angle, one wedge being movable along its length by a micrometer...

A device that permits only electrons within a narrow velocity range to pass through it, while rejecting those above and...

Computerized lens design algorithm that permits the lens MTF characteristic to be included and controlled during the...

Capability requirement for optical switches for transmission lines to process arbitrarily polarized light because of the...

An imaging technique used in radiology that is based on the principles of nuclear magnetic resonance (NMR) to produce...

A device designed to enlarge the image of a microscopic object by television process. It may be a flying spot scanner that...

In television, a lateral displacement of the lines from their normal position due to the instability of a synchronizing...

Calculation of peak and average transmission power at a given point along an optical fiber or cable.

Pitch, wax, resin or other cement suitable for holding optical parts to a spindle during grinding and polishing processes.

An imaging process, similar to specific Doppler mapping radar techniques, that utilizes a laser, an optical imaging system,...

A reproduction made of an original grating -- usually by casting thermosetting plastics onto the original -- to avoid the...

For a single-mode fiber, the measurement of the irradiance distribution at the fiber's end face.

A spectrometer or autocollimator used to measure prism angles.

A technique used to create a series of interrelated holographic images that give an appearance of motion when projected in...

A coating made up of many layers of material having alternating high and low refractive index. In this way, it is possible...

A technique for measuring the energy spectrum of electrons emitted during the absorption of ultraviolet radiation. This...

The number of channels per unit bandwidth handled by a single optical fiber.

The determination of distance based upon the known size of an object and the size of its image at the image plane of an...

A computer architecture used in parallel processing whereby all the processing elements are operating under their own local...

An instrument that uses a photocell to detect and measure the intensity of incident light.

The Weissenberg method, named after the German physicist Karl Weissenberg, is a technique used in x-ray crystallography for...

A spectroscopic technique that combines the high chemical specificity of Raman scattering and signal sensitivity provided by...

A lens or lens system that produces an enlarged virtual image of an object placed near its front focal point.

A photoelectrically controlled, alphanumeric reading device that converts characters to audible or sorting signals which can...

The image error that results from astigmatism, coma, oblique spherical aberration, lateral color and distortion.

A photoemissive cell having an inert gas added to its envelope. Subsequent ionization of the gas increases the responsivity...

An instrument designed to measure the rate of rotation of components, such as shafts.

The fluorographic method whereby the visible image (as opposed to the x-ray image) is photographed by mounting a camera in...

A circular lamp or bundles of optical fibers placed around the perimeter of an objective lens to illuminate the object field...

A technique for removing thermal noise and drift from focal plane assemblies by sampling the system output between views of...

A compound crystal having two or more crystals or crystal sections that, when regularly positioned, are in reverse position...

Condition in which two stimuli appear to match in color to a specified observer, or in which two objects appear to match in...

A small mass spectrometer, with a limited mass range, equipped with an analyzer to generate a cycloidal-path beam of the...

1. A plane that forms one side of the groove ruled on a diffraction grating. 2. To form the individual grooves of a grating...

A grating with ridges of rectangular cross section, generally equal in width to the space between. This type of grating may...

Photochromic refers to a property exhibited by certain materials, typically organic compounds or dyes, which undergo...

Periodic interruptions of a light beam incident on an absorbing medium that produce heat, expansion and acoustic wave...

The positioning of two Nicol prisms so that their axes are at right angles to each other. With this arrangement, light...

A unit of energy absorbed from ionizing radiation, equal to 100 ergs per gram of irradiated material.

Dichroism refers to the property of certain materials to exhibit different colors or absorbance of light depending on the...

An imaging system that uses a mosaic of tiny light-sensitive semiconductors (phototransistors) to produce individual outputs...

A CCD sensor that provides feedback to the motion control system for a telescope, allowing the telescope to follow a...

A light source that does not fluctuate despite temperature changes.

A mask-alignment microscope used to produce and inspect microcircuits in the electronics industry. It provides flat-field,...

1. A bundle of light rays that may be parallel, converging or diverging. 2. A concentrated, unidirectional stream of...

A local area network topology in which all nodes are tapped off a single cable, and all hear every transmission on the cable.

Noise generated in the flow of current in the photomultiplier, produced by the intentional or controlled application of...

An aptamer is a short, single-stranded DNA or RNA molecule that can bind to a specific target molecule with high affinity...

A disc composed of a series of holographic optical elements that diffract light at various angles. When spinning, a raster...

A CCD that has been reduced in thickness by etching so that light passes through the back layers of the CCD. This type of...

The interaction between a photon and an energetic electron, caused by collision, that transfers energy from the electron to...

E.I. duPont's trade name for an aramid yarn used as a strength member in the jacket of fiber optic cable.

Unlike the thermocouple or bolometer, the pyroelectric infrared detector is a current source with an output proportional to...

A device used in measuring the attenuation of multimode optical fibers. A short reference length of fiber when combined with...

The equivalent f number of a fictitious lens that has a circular opening and 100 percent transmittance, which would give the...

Any of the numerous powders used for grinding and polishing glass, crystal or metal, the chief material being emery and...

The effect, present in particular phosphors, that is defined as a transformation in the dielectric constant of a material...

A technique used in integrated optics where a groove is cut on a substrate surface and covered by a thin film to facilitate...

Filtering procedures aimed at estimating the original image by removing the blurring and noise suppression that occur during...

1. A method of photographing distant objects with a lens of long focal length. 2. The reproduction of photographs over a...

In television system specifications, the number of parallel horizontal black and white lines of equal thickness, that can be...

An exposure meter that indicates the amount of light reflected from the subject of interest.

In an interference pattern, that point where there is no difference between the optical paths of the interfacing wavefronts.

A concept used for purposes of preliminary calculations and analysis. In theory it is a lens whose axial thickness is zero.

The selective absorption of electromagnetic waves by a liquid made up of molecules with permanent dipole movement.

A television system that uses a slow rate of horizontal scanning to increase its reproduction and transmittance accuracy of...

An electric discharge in a low-pressure gas having a low-current density and a space potential near the cathode that is much...

Formula used in convection study to express the ratio of buoyant force to viscous force.

Fluorescence produced by a material that has been treated with a dilute solution of fluorescing material.

An acronym for radioactive detection, identification and computation. The term refers to the detection and measurement of...

The process by which a substance, usually a solid, attracts and retains on its surface the molecules of another substance.

The process whereby a blank or disc is heated to a sufficiently high temperature to sag into a mold having a desired...

In a laser, the series resistance necessary for a stable electrical discharge.

1. A stereoscope that has adjustable scales to allow the determination of distances and dimensions from stereoscopic...

The radiation-free transition that takes place within an ion, in which inner-shell vacancies in neutral atoms are filled by...

In computer imaging, a value representing opacity.

Imaging radar that increases the sweep of its along-track (or azimuth) capacity by measuring not only the time delay of the...

A device that couples a light source to an optical fiber by projecting an image of the source and the fiber core onto a...

A photometer that permits visual comparison of the luminance of two surfaces.

The study and the interpretation of the infrared emittances of celestial bodies and phenomena.

A computer whose architecture contains several CPU chips arranged in parallel. Often used in image processing systems.

The photographic recording of data, in binary form, for storage in memory. Exposure is achieved by a cathode-ray tube or by...

With respect to a crystal, having three unequal axes intersecting at angles, only two of which can be equal and only one of...

The transparent front layer of the eye. Light entering the eye is refracted (converged) by the outer surface of the cornea.

Multiple scattering method used in biological analysis in which approximations yield simple, explicit solutions, at least...

Two formulas used in diffractometer analysis, the first giving the individual diffraction patterns of each aperture, the...

The magnetic flux that, linking a circuit of one turn, produces in it an electromotive force of one volt as it is reduced to...

The process or device by which more than one signal can be sent over a single channel by using different time intervals for...

Reflectance spectroscopy is a technique used to analyze the reflective properties of materials across various wavelengths of...

Micro-LED (micro-light-emitting diode) refers to a technology that involves the use of very small light-emitting diodes to...

A medium that scatters or absorbs radiation that passes through it.

A perfectly diffusing surface; the intensity of the light emanating in a given direction from any small surface component is...

A custom optic refers to an optical component that is designed, manufactured, and tailored to meet specific requirements or...

One or more spots placed in the field of view of an optical system to provide a means of reference.

An intensified charge-coupled device that uses a large negative charge at the grid to switch off the flow of electrons at...

A transmission interference microscope that produces interference patterns of a sample by using birefringent plates that...

Laser powder bed fusion (LPBF) is a type of additive manufacturing (AM) or 3D printing technology that uses a high-power...

A portion of computer memory that is used for temporary storage of frequently accessed data. Substantially increases...

The intensity regulation of a cathode-ray tube by alteration of the grid-cathode voltage.

A disc, having opaque and transparent sectors or sectors with unlike reflectances, that is rotated at a specific rate to...

A very uncommon lamp in which a tungsten electrode is heated to incandescence by a radio-frequency electrical current.

An instrument that measures the wavelengths of an x-ray spectrum by the diffraction of x-rays from a crystal with a given...

A network interface card (NIC), also known as a network adapter or LAN adapter, is a hardware component that allows...

The record formed on paper by a scanner.

A terahertz spectrometer is a scientific instrument used to measure and analyze the properties of materials in the terahertz...

Excimer laser coronary angioplasty (ELCA) refers to a medical procedure used in the treatment of coronary artery disease....

A galvanometric scanner, also known as a galvanometer scanner or galvo scanner, is a type of optical scanning device used to...

The propagation constant evaluated along the axis of a waveguide, that is, in the direction of transmission. Also called...

An optical test table made up of two outer layers or "skins'' bonded to either side of a honeycomblike core, usually of...

The reflection in different amounts as a function of wavelength, as a result of absorption and scattering, leading to color...

A lens aberration that results in the tangential and sagittal image planes being separated axially.

The method of disintegrating the substance of the cathode by bombarding it with ions and depositing it on another electrode...

A system of Japanese origin that utilizes Fresnel lenses and a fiber optic network to transmit sunlight to otherwise...

Approximation of a system of thermal equilibrium formed by the distribution of the kinetic energies of electrons in a gas...

A system employing a dark trace tube in which the opacity of the screen is varied as a function of the power of the beam.

A microscope used either to detect selective absorption of various wavelengths by the specimen or to achieve increased...

Time-lapse optical coherence tomography (OCT) refers to a medical imaging technique that captures a series of sequential OCT...

Transmission accompanied by diffusion or scatter to the extent that there is no regular or direct transmission.

Any filter in which the range of frequencies within a chosen radius suffers no attenuation and the range of frequencies...

The normal condition of vision where an object at infinity is in sharp focus with the eye lens in a neutral or relaxed state.

A category of systems designed to communicate a photo taken from the air (e.g., aircraft, balloon, satellite) to a ground...

In a lens, the square of the radius of its aperture divided by the product of the focal length and the wavelength. It...

A noncrystalline, inorganic mixture of various metallic oxides fused by heating with glassifiers such as silica, or boric or...