An approach to character recognition based on the structure of the character to be identified (number of straight lines, bays, holes, etc.); used where simple matching is not viable, as in handwritten documents.

An OLED display formed by creating an array of OLED pixels connected by intersecting anode and cathode conductors arranged...

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

A grating beamsplitter is an optical device that utilizes the principles of diffraction to split a beam of light into...

The optical reconstruction of image information contained in a sound field. First the diffraction pattern, formed by an...

The technique that uses light to detect and analyze the antibodies produced by a specimen stained with an organic dye.

The optical Fourier transform is a mathematical operation applied to optical signals that involves transforming a spatial...

Thin-film coating, single or multilayer, that is applied to a substrate to increase its reflectance over a specified range...

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

It is often necessary to estimate the value of what a pixel would be between neighboring pixels. This is accomplished by...

A semiconductor platelet laser that emits a coherent image by means of plane optical pumping over the platelet surface, and...

The broadening of spectral lines due to the collision of radiating particles with one another and the resulting interruption...

A characterization of the throughput performance of data storage systems; the EDR is the total of data retrieved divided by...

The frequency space between consecutive transmission peaks in the transmission spectrum of a Fabry-Perot interferometer or...

A photographic process using x-ray radiation or the g-rays of radioactive materials.

Any lamp whose emission of radiant energy is dependent upon the passage of an electrical current through the emissive medium.

Similar to LASCR, except that all four regions are available.

The technology of manipulating light on a micro scale. In optical communications, this is usually accomplished using two or...

An optical lens manufactured to control the transmission of light over a specified wavelength range. Low absorption lenses...

A prism that often is used as a dispersing element in spectrographs and monochromators.

The use of high temperatures, between 2000 and 3000 °C, to excite emission lines from a sample in spectroscopic...

An instrument used to detect and measure the energy distribution of gamma rays. It has been used to chart the radioactivity...

A device that uses a photoelectric cell to determine the level of oxygenation in the blood.

An instrument designed to analyze the optical effects of color.

An operational mode for radiometers that analogs the method of operation of an angstrom pyrheliometer. In this mode, the...

Thin-film coatings are layers of material applied to the surface of an object or substrate, typically to modify its optical,...

Unlike the thermocouple or bolometer, the pyroelectric infrared detector is a current source with an output proportional to...

A wedge in a rangefinder or heightfinder used to displace the image produced by one telescope so that it coincides with that...

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

The noise produced in a photodetector when the photocathode is shielded from all external optical radiation and operating...

In a radiation detector, the ratio of the output to the input signal.

Photosynthetically active radiation (PAR) is the 400- to 700-nm region (visible light) of the electromagnetic spectrum that...

The bending of oblique incident rays as they pass from a medium having one refractive index into a medium with a different...

A semiconductor is a type of material that has electrical conductivity between that of a conductor and an insulator. In...

Photoimmunotherapy (PIT) is a medical treatment approach that combines elements of phototherapy and immunotherapy to target...

Two lenses, separated by a distance equal to the sum of their focal lengths, and retroreflecting mirror assemblies, one of...

Integral densities that are measured relative to arbitrarily selected red, green and blue filters.

The inductance of a closed circuit in which an electromotive force of one volt is produced when the electric current in the...

In a lens or lens system, that surface at which the projections of an entering and exiting ray intersect. Also known as the...

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.

Diamond turning, also known as diamond machining or diamond cutting, is a precision machining process used to produce...

The amount of time needed for a detector signal or electronic circuit to reach 63 percent of its final value after a fixed...

A light beam whose electric vectors are broken into two elements of unlike amplitudes that are perpendicular to each other...

The constant equal to the unit stress divided by unit deformation, relative to all values and a substance's proportional...

The luminous flux emitted by a light source in all directions.

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

The higher throughput obtained with an FTIR device compared with traditional spectrometers that need slits to achieve...

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

An array of optically distinct fibers that are fused into one strand. They are used to keep the resolution efficiency of the...

A device that changes the frequency of light by inducing the Raman effect on a beam passing through it.

A model that predicts laser-induced damage to thin films caused by irradiation of identical, randomly distributed film...

The series of rings or bands formed when light beams reflected from two polished, adjacent surfaces, placed together with a...

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

Optoelectronics is a branch of electronics that focuses on the study and application of devices and systems that use light...

The angular change of an incident beam due to vibrational induced refractive index changes within a crystal.

An electronic device consisting of a semiconductor material, generally germanium or silicon, and used for rectification,...

The process in the manufacture of an optical system that gives it the required geometric shape.

A semiconductor laser that operates in the infrared and that is pumped with strong pulses of radiation from a second laser....

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

A term applied to the recording of video images by means of magnetic tape or disc, so that the image's record can be played...

A sheet of thin brass, one edge of which has been accurately cut to a known and marked circular radius. It is used to check...

A restricting wavelength above or below which a specified form of radiation is totally almost absorbed by a specified medium.

An electrostatic device that uses an electric potential barrier to allow the transmittance of electrons at or above a set...

The face of a cathode-ray tube (CRT) that has a fiber optic sheet attached to its surface. The sheet's fibers are at right...

An instrument used to measure the luminance (brightness) of a distant object. The object is viewed through a small...

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

An instrument that measures several optical parameters, such as optical power and wavelength, with a single measurement...

A photometer that uses a wedge, marked to show its reduction of flux density, to make two light sources equal in intensity...

The velocity from object to observer, directed along the line of sight.

Photovoltaic (PV) refers to a technology that converts sunlight directly into electricity using semiconductors. The term...

A digital twin refers to a virtual representation or digital counterpart of a physical object, system, or process. This...

In image processing, the effect caused by large jumps between gray levels, rather than a gradual change.

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

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

A microscope equipped with a polarizer, an analyzer and a Bertrand lens to focus on the upper focal plane of the objective....

A photonic crystal that comprises magneto-optical material such that the optical response of the device depends on the...

The production of a positron-electron pair by a photon having energy greater than one mega-electron-volt, whereby some of...

Counter propagating beams imaged along the same path in order to detect rotation. Precise rotation is measured through...

A galvanometer having a small mirror that is mounted on a moving element and that reflects a light beam onto a scale.

A process used in pyrometry and photothermometry to create a photographic record of a surface's temperature gradients....

Microscopy is a scientific technique that involves the use of microscopes to observe and study objects that are too small to...

A surface that envelops a bundle of rays or bundle of normals to the wave surface. It may be observed as a hollow, luminous...

In spectroscopy, the false images arranged symmetrically on both sides of the true line and caused by irregularities in the...

A chart formed by a spectrograph; the record of the spectral range. See spectrograph.

The term photochemical pertains to chemical processes or reactions that are initiated or influenced by the absorption of...

A test chamber designed to expose the subject being tested to external conditions, such as heat, shock, pressure and...

An incandescent or carbon arc lamp designed with a stable and compact arc or filament that permits it to be used as a light...

A molecule that is the mirror image of another molecule. The two mirror-image molecules have the same chemical properties;...

A tough, durable, heat- and cold-resistant optical quality plastic used in injection-molded items such as streetlight...

A scanning technique in optical character recognition in which an array of photocells is used to scan each character to...

An image intensifier tube in which the photocathode and the output of the microchannel plate are proximity-focused on the...

1. The decrease of the absorption (or gain) coefficient of a medium near some transition frequency when the power of the...

A fish-eye lens designed to photograph cloud formations over the entire visible sky.

An instrument that measures the wavelengths of an x-ray spectrum by the diffraction of x-rays from a crystal with a given...

Photogrammetry is a technique used to obtain accurate three-dimensional measurements of objects and environments through the...

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

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

Production of a repeated image of a transmitted beam through a diffractive optical element such as a holographic card or...

In optical communication systems, operations in which the amplitude of the pulses, as opposed to their width, determines the...

A scanning probe microscope that analyzes the surface of a specimen by recording the intensity of light as it is focused...

The restricting aperture located at the front of the lens. It is usually defined as the maximum diameter of the entrance...

A technique developed to measure the molecular weight of macromolecules by analyzing the spontaneous fluctuations that occur...

A technique for measuring the concentration of any gases. Identical infrared beams are alternately chopped, one passing...

The light from a nonselective diffuse reflector due to the standard illumination of the scene to be televised.

Also known as electronic photometer. A photometer with a photocell, phototransistor or phototube for measuring the intensity...

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

Pertaining to the manner in which light is reflected, as by a mirror or speculum.

The process or act of measuring the geometric properties of an object or image.

A type of motion-picture camera in which single frames are photographed either automatically at a predetermined rate (as...

A diagram that shows actual component signals and the basic wiring configuration of a relay logic circuit.

A mirror coated to reflect cold (white) light while transmitting hot (infrared) energy.

Also known as reversed telephoto lens. A lens consisting of an ordinary objective with a negative component near its front...

Reflectance in a specified direction, for a specified direction of incident illumination.

In optics, a collapsible structure situated between the lens and film of a camera to allow variation of the distance between...

The power, expressed in prism diopters, that is the linear displacement, in centimeters, produced by the prism one meter...

The transformation of incident radiant energy into a photoelectric emission current.

A fiber optic cable assembly refers to a complete unit consisting of optical fibers, connectors, protective jackets, and...

The process of subjecting glass to temperature cycling to produce physico-chemical reactions that alter its properties....

Acronym for profile resolution obtained by excitation. In its simplest form, probe involves the overlap of two...

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

A method of demonstration or examination using a point source illumination without the use of any projection lens between...

A wavelength region of relatively high transmittance, surrounded by regions of low transmittance.

In a semiconductor, the state created by the addition of a dopant that provides excess electrons.

An image that is formed when rays emerging from an optical system are diverging from the optical axis. The virtual image is...

A mass spectrometer utilizing both radial electrostatic and magnetic field analyzers to improve the focusing and increase...

A type of fiber optic sensor that detects alteration in position, distance, pressure, liquid level or temperature by...

A form of lens assembly used in a projection system to maximize efficiency and assure uniform illumination of the object...

For a particular mode, the reciprocal of the rate of change of the phase constant with respect to angular frequency.

A method of taking radiographs at a distance from the object being photographed to decrease distortion.

The time domain is a concept used in signal processing and analysis to describe signals in terms of their behavior over...

A surface heat-treating process that produces a highly stressed surface. In case-hardening of glass, a plate of glass is...

The number of unique ways in which a part can move in an alignment system. In static alignment, there are six: one in the...

A corner cube, also known as a corner reflector or retroreflector prism, is a type of optical device used to reflect light...

A diode laser is a type of laser that uses a semiconductor diode as the active medium to generate coherent light....

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

A fundamental law of quantum theory which states that the discrete quanta of energy transfers associated with...

Optical fiber optic switches are devices used in optical fiber communication systems to selectively route optical signals...

Inactive optically, but having the capacity for resolution into forms of opposed optical activity. The term is derived from...

The unwanted and unpredictable fluctuations that distort a received signal and hence tend to obscure the desired message....

Also called complementary dominant wavelength. On a chromaticity diagram, the wavelength on the spectrum locus that lies on...

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

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

In optics, an octave typically refers to a range of frequencies or wavelengths that spans a factor of 2. In other words,...

A measure of the dispersive properties of a glass. The relative dispersion is defined as: where C, D, and F refer to the...

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

The use of a micromanipulator in combination with a microscope for the purposes of examining, dissecting, or the...

1.) Generally, the electromagnetic spectrum within the wavelength region extending from the vacuum ultraviolet at 40 nm to...

A noncontact, nondestructive method of measuring defects in thin composite materials, using a xenon flashtube to generate...

The study and measurement of spectra and their components.

An instrument for plotting the rotatory dispersion of a substance at different wavelengths.

A caustic formed by reflection.

An airspaced achromatic doublet telescope objective.

A semiconductor device with a semiconductor junction in which infrared radiant flux is nonthermally produced when a current...

The splitting of energy levels of an atom, ion or molecule because of a magnetic field.

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

A pair of long, slender parallel apertures used in experiments on diffraction and interference.

The determination of the degree to which a manufactured component can deviate from its ideal specifications of material and...

The spontaneous visual presentation of radar information by electronic traces on a cathode-ray tube.

A product of the area of a light beam (normal to its direction of propagation) and the solid angle that the beam includes;...

A photographic or electronic recording of an optical interference pattern.

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

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

Epitaxial deposition is a process used in semiconductor manufacturing and materials science to grow a thin crystalline...

Color correcting; chromatic aberration corrected.

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

Microfluidics is a multidisciplinary field that involves the manipulation and control of very small fluid volumes, typically...

Device that uses a coherent reference wave to record the interference patterns produced by incident ultrasonic waves on an...

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

An optical system that is corrected chromatically for three colors simultaneously.

Frame rate refers to the frequency at which consecutive images, or frames, are displayed in a video sequence. It is...

The spectrographic analysis of matter that is in a cooled state. Generally, a mechanical refrigerator is used to lower the...

An eyepiece combined with an erecting prism or lens system.

Two formulas used in diffractometer analysis, the first giving the individual diffraction patterns of each aperture, the...

An optical system that rapidly alternates two similar pictures or scenes to permit the detection of small dissimilarities...

A monolithic device containing both photonic and electronic sources, detectors, modulators, etc., on a single semiconductor...

Film in which electric polarization is reversible when influenced by an electric field.

A laser that emits energy in a series of short bursts or pulses and that remains inactive between each burst or pulse. The...

A technique for removing thermal noise and drift from focal plane assemblies by sampling the system output between views of...

The law stating that the amount of chemical change produced is proportional to the amount of light absorbed. Actually, the...

When a stereo pair of images is switched so that the right eye sees the left image and the left eye the right, the stereo...

A type of fiber optic sensor that detects changes in pressure, vibration, sound level or acceleration by monitoring the...

A plate of electro-optical material that serves to rotate the plane of polarization of a light beam.

Cold atoms refer to atoms that have been cooled to extremely low temperatures, typically in the microkelvin (µK) to...

A narrow linewidth optically transmissive or reflective component intended for use with a highly monochromatic or single...

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

A high-resolution spectroscopic device commonly used in the early 20th century as a component of double-beam...

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

One surface of a nonconducting plate that is coated with many minute particles of photoemissive material that are insulated...

In compact disc systems, the two principal frame formats for data storage. Mode 1 devotes 2048 bytes to user data, reserving...

In present usage, especially for spectroscopic identification, an arc between electrodes that serves as a radiation source....

A manufacturing process used to construct substrates for large optical components. Used with IR materials, planform bonding...

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

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

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

The two points on the principal axis of a mirror or lens so positioned that light emitted from either point will be focused...

Light that is emitted from a phosphor film applied to the surface of a three-layer thin film, respectively metal, oxide and...

An instrument used to record the emittance or reflectance of an object by scanning with discrete spectral resolution over a...

The scattering of charged particles, moving through matter, by the electrostatic force exerted by other charged particles.

The transparent front layer of the eye. Light entering the eye is refracted (converged) by the outer surface of the cornea.

The light wavelength for which the direction of reflectance from the groove face is identical to the angle of diffraction...

A device that converts stored electrical energy into light by means of a sudden electrical discharge.

A laser-pumped crystal with nonlinear optical properties inside of an optical resonator in which the output generates...

Calorimetry is a branch of science that involves the measurement of heat flow in physical or chemical processes. It...

The inhibition or elimination of one process by another process. The stimulated emission of a laser oscillator can be...

A power loss caused by transverse or lateral deviation from optimum alignment of source to optical waveguide, waveguide to...

In analysis, the carbon layer that is evaporation-deposited on a specimen to protect and ready it for study by electron...

The conduction of electricity in a gas as a result of the ions generated by collisions between electrons and gas molecules.

An electric discharge in a low-pressure gas having a low-current density and a space potential near the cathode that is much...

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

The electron stream emitted by a phototube when the cathode is exposed to light.

A spectrum that originates from molecules and that is composed of bands which, in turn, consist of many closely spaced...

Mode-locking is a technique used in lasers to produce ultrashort pulses of light with durations on the order of picoseconds,...

A mechanical, electrical, thermal or optical detector designed to identify and measure ultrasonic radiation.

Structural color refers to coloration in materials that is not caused by pigments or dyes but is instead a result of the...

A lamp used in projection that is made with a reflector built into the bulb, normally by coating a portion of its interior...

A diffraction grating is an optical component consisting of a surface with a periodic structure of equally spaced, parallel...

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

A device used to count objects that pass a given point by allowing each object to obstruct a beam of light falling on a...

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

A tank with a boiling solvent at the bottom and a ring of cold piping higher up that condenses the liquid and returns it to...

For a Fabry-Perot interferometer or etalon, a value for the transmission bandwidth which can be calculated as the ratio of...

The electrical arc formed between metal rods that emits the spectrum of the metal itself. Commonly used in the chemical...

The utilization of the light produced when electrical energy is directly converted into light within devices used for visual...

The constant that, multiplied by the frequency of the radiation-producing emission of photoelectrons, determines the amount...

An instrument used for viewing in low levels of illumination by means of infrared radiation. A high-aperture lens forms an...

A well-corrected flat-field eyepiece with good eye relief. Similar to a Huygenian.

An optical instrument for forming the spectrum of a light source and recording it on a film. The dispersing medium may be a...

Characterizes the significant solar radiation at the surface of the earth, so named because its spectral range extends only...

Single molecule localization microscopy (SMLM) is a group of super-resolution microscopy techniques that surpass the...

The lowest anode voltage at which a gas tube can sustain a discharge.

The number of electrons that can share a principal quantum number by preventing identity between any two electrons' four...

A polishing material that has a quicker polishing action than rouge (ferric oxide) and that is cleaner to handle.

A device similar to the ordinary spectrophotometer but containing particular modifications to provide for the comparison of...

1. In optics, the bending of light rays toward each other, as by a convex or positive lens. 2. Turning in the eyes to view a...

Freeform optics refers to the design and fabrication of optical surfaces that do not follow traditional symmetric shapes,...

In fiber optics, a material whose properties, usually of transmission, are distinctly affected by the absorption of water...

A photoelectrically controlled, alphanumeric reading device that converts characters to audible or sorting signals which can...

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

A high-speed motion camera, also known as a high-speed camera or slow-motion camera, is a specialized imaging device...

In vivo is a Latin term that translates to "within the living." In scientific contexts, particularly in biology and...

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

A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of...

A 2D profile sensor is a type of sensor used in various industrial and technological applications to measure and capture...

1. The direct storage of data as bits in memory using optical systems and properties. The memory makes use of a laser beam...

The photographic recording of a visible image formed by the impact of invisible radiation on a fluorescent screen.

A homogeneous optical medium or coating that transmits only in particular regions of the spectrum. It is used to change or...

In rudimentary form, this technology consists of diffusion of a PN junction through a mask of silica, over which a contact...

Standard maintained by the International Commission on Radiological Units as a unit of radioactivity defined as the quantity...

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

Blaze height typically refers to a parameter in the context of diffraction gratings, which are optical devices consisting of...

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

A concave mirror that has the form of a paraboloid of revolution. The paraboloidal mirror may have only a portion of a...

Attosecond-pump attosecond-probe spectroscopy (APAP) is an advanced technique in ultrafast spectroscopy that allows...

The formation and display of three-dimensional images by ultrasonic energy. In one technique, the energy pulses from an...

A special laser glass made primarily of fluoride compounds that exhibits extremely low refractive index and allows greater...

A small television tube originally developed for closed-circuit television. It is about 1 inch in diameter and 5 inches...

A device that utilizes avalanche multiplication of photocurrent by means of hole-electrons created by absorbed photons. When...

The reproduction of a picture or image, produced by scanning the image and converting it into electrical signals that carry...

In fiber optic cable, containment of the fiber or fibers within an outer protective tube in which they can move to some...

A sputtering target is a solid material used in the process of physical vapor deposition (PVD), specifically sputtering....

Wide-field fluorescence microscopy uses either naturally occurring structures or staining with fluorescent tags that are...

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

Radioactivity formed by the bombardment of stable elements by either neutrons or high-energy, charged particles under...

A laser radar application in which a sequence of direct measurements of target position is fed into a tracking filter to...

A set of photodiodes with no gaps between them that can sense the displacement of a spot of light anywhere on the sensing...

A transparent crystalline substance that is anisotropic relative to the velocity of light.

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

Lithography is a key process used in microfabrication and semiconductor manufacturing to create intricate patterns on the...

The random noise having a spectral density that is substantially independent of the frequency over a specified frequency...

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

An impurity in a material that is capable of inducing electrical conduction in that material by transferring an electron to...

The minimum of change in stimulation needed to effect an awareness of change in sensation that is statistically determined.

The length of the small space within which the atmosphere exhibits coherence, particularly in relation to an observer on...

When, for example, a beam of monochromatic light passes through a diffraction grating, the emergent rays that have remained...

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

A type of exposure meter that artificially reduces the light admitted in a sequence of known fractions until a value is...

Electromagnetic radiation detectable by the eye, ranging in wavelength from about 400 to 750 nm. In photonic applications...

A catadioptric lens assembly consisting of a Maksutov corrector and a spherical primary mirror.

A method used in integrated optics; formed by growing an epitaxial layer of active material, removing it from its base and...

A chamfer or protective bevel.

A process used in the design, repair and customization of integrated circuits. A low-power laser etches a silicon wafer...

The induced birefringence in isotropic gases that results when the gases are placed in strong fields.

A device that uses four electrodes set in an alternating positive-negative polarity series to focus the beams of charged...

A ring laser gyroscope (RLG) is a type of gyroscope that uses laser light to detect and measure changes in orientation. It...

A refrigeration method based on the Peltier effect. When an electric current passes through a thermocouple of two dissimilar...

The coupling of laser or light beams via nonlinear optical techniques such as four-wave mixing to achieve spatial variation...

A power intensity pattern produced by the mutual interference of partially coherent beams that are subject to minute...

Waves that propagate along the interface between two different media without radiation with exponentially decaying...

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

An instrument that reads alphabetic, numerical and special characters by means of a photosensor that measures the varying...

Cemented prisms of differing refractive indices which refract incident light and, due to differing refractive indices, will...

1. To influence to a single direction. 2. Voltage that is applied to a solid-state device.

The subtractive imbibing process of transferring color prints on paper whereby the dyes from three separately prepared...

The study of chemical changes produced by radiation.

A method of coding information in a communications system where the shift in the phase of an electromagnetic wave represents...

Wide-field, low-magnification device that consists of two compound microscopes focused on a single object, producing an...

An image-forming system having curved mirrors in place of transparent glass components. Mirror lenses are commonly used for...

A graphic reproduction of an object formed by a microscope or another optical system. Also an instrument used to make tiny...

A cathode-ray tube that either splits an electron beam from one source or uses beams from two sources to produce two beams,...

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

The force acting upon a charged particle as it moves in a magnetic field, proportional to the particle's charge and velocity.

High-modulus elastic fibers that exhibit the following differences from conventional elastic fibers: Increasing temperature...

A device for measuring diffraction grating efficiency at any angle of incidence, consisting of a reflectometer wherein the...

An instrument used to record rapidly varying currents or voltages. An oscillograph may consist of a cathode-ray tube...

A laser diode with an output beam contained in the active layer by means of a built-in refractive index profile formed in...

The detection and measurement of nuclear and x-ray radiation.

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

A light-sensitive detector having a chemical compound that reacts when exposed to light. It is used in photochemistry and...

A technique for improving the structure density of thin-film coatings by bombarding the growing film with accelerated ions...

A plate made of a double-refracting crystal having such a density that a phase difference of one-quarter cycle is formed...

That property of a material that determines its ability to release electrons when absorbing photons.

A temperature radiator whose spectral emissivity at all wavelengths is in constant ratio (less than unity) to that of a...

In the SI system, prefix meaning one hundred, 102.

1. With respect to angular subtense, a source of light, such as a star, that is very small. In a lab, a point source may be...

A loss of resolution or detail in a television signal caused by the size of the electron scanning beam.

An eyepiece used in a polariscope or polarizing microscope to give a comparison view of the same object under illumination...

Signal used in optical transmission systems to generate currents in a detector that are decoded with reference to a...

The figure of merit of a resonator, defined as (2p) x (average energy stored in the resonator)/(energy dissipated per...

An optical interference technique widely utilized as a method of nondestructive testing when determining the ray deflection...

A telescope stand equipped with a polar axis that can be set parallel to the Earth's axis of rotation and a declination axis...

That branch of metallurgy that uses electron microscopic techniques in the examination of the nature of metals.

A special evacuated camera equipped with means for holding a specimen and bombarding it with a sharply focused beam of...

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

The process of making an abrupt break in a spherical surface on a spectacle lens so that a new center of curvature is set...

A device designed to concentrate and direct a light source by enclosing the source in it and using a concave reflector to...

The use of a krypton laser system for the measurement of small molecules aligned by an electric field, by analyzing the...

A flexible display refers to a type of electronic visual display that is designed to be bendable, foldable, or rollable,...

In solar energy technology, the percent of usable land covered by collectors. The horizontal collector is the only design...

Nonlinear optics is a branch of optics that studies the optical phenomena that occur when intense light interacts with a...

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

Quantum confinement refers to the phenomenon in quantum mechanics where the motion of charge carriers, such as electrons or...

An optical experiment carried out conclusively in 1887 that demonstrated that the ether, a hypothetical medium postulated by...

In a fiber optic communications network, a circuit that connects two switching centers and does not branch off to terminal...

With respect to atomic fluorescence spectroscopy, the fluorescence that is emitted by an atom at a spectral line of a...

1. The process by which an atom acquires energy sufficient to raise it to a quantum state higher than its ground state. 2....

Optical materials refer to substances or compounds specifically chosen for their optical properties and used in the...

The electrical distribution that serves to influence an electron beam in the same way that an optical lens affects a light...

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

A spectrophotometer specially designed to measure spectral reflectance.

An objective measure of an object's brightness that is derived from the ratio of the luminance of its lightest section to...

A lamp that uses the transmission of an electric current through a gas or vapor to produce illumination. Neon, mercury and...

A thick meniscus lens arranged concentric with the center of curvature of a spherical mirror to produce an image free of...

An electron-beam tube in which the current to an output electrode is regulated by the transverse motion of the tube's...

The photomicrographic recording of Schlieren effects, irregular refractions of light from optic surfaces or areas of thin,...

The ratio of an object's radiance to that emitted by a blackbody radiator at the same temperature and at the same wavelength.

A hologram that is illuminated by a source from the viewer's side.

An accelerometer is a sensor or transducer that measures the rate of change of velocity of an object, or in simpler terms,...

The study of the transmission of radiant energy through crystals, especially anisotropic crystals, and their effects on...

A laser using a dye solution as its active medium. Its output is a short pulse of broad spectral content and its achievable...

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

Entirely analogous to color photography, but inclusive of light bands that do not appear in the visible spectrum.

A single positive lens or group of lenses used in a projection system to collect light from a source and cause it to...

The transition boundary between P-type and N-type materials in a semiconductor.

Optical glasses containing the oxides of rare earths such as lanthanum to impart a very high refractive index combined with...

See periscopic lens; rapid rectilinear lens.

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

The analysis of light in the blue region of the visible spectrum.

A double-surfaced catadioptric spherical mirror whose spherical first surface consists of a negative meniscus (concave) lens...

A scattering photometer using scattered light in the solid angle 4.51+0 19° with respect to the forward direction, and...

A transparent dielectric film, bounded by material of a lower index of refraction, capable of guiding light.

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

The ability of a machine to perform certain complex functions normally associated with human intelligence, such as judgment,...

A spectrum band that is usually found in the visible or the ultraviolet because of the electron transitions taking place...

A microscope objective designed to be used without liquid between the cover glass and the objective, or, in the case of...

A spectrograph using a prism that has an internally reflecting surface and that serves as a constant deviation prism.

An imaging system that uses a mosaic of tiny light-sensitive semiconductors (phototransistors) to produce individual outputs...

A piece of glass with a high refractive index that is fused to the major blank.

A shutter actuated by means other than mechanical springs for timings on the order of nanoseconds. The shutter is used in...

A CCD sensor that provides feedback to the motion control system for a telescope, allowing the telescope to follow a...

A waveguide having a characteristic that is altered continuously with the distance traveled, relative to the axis of its...

An image of an object that appears above the object's true position as the result of abnormal refraction of the image rays...

In optics, "mode beating" refers to an interference phenomenon that can occur in laser systems with multiple longitudinal...

The law stating that when light strikes a surface at such an angle that the reflected and refracted rays are perpendicular...

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

In coherent optical communications systems, a laser used at the receiving end to produce a steady wave that is combined with...

The pulse-to-pulse fluctuations in power distribution among modes of a Fabry-Perot laser, which can result in...

A photometric instrument used to measure the illumination falling on a surface. It may be photoelectric or visual.

In optical character recognition, the mechanical or electronic transducer used to detect the level of illumination present...

A nonradiative transition refers to a process in which an electron or an atom undergoes a change in its energy state without...

The observation of a reproduced television picture on the face of a cathode-ray tube.

Contraction of "picture element." See pixel.

Operates with light collectively emitted by the recombination of free electrons and ions in the plasma state.

The process of heating and slowly cooling a solid material, like glass or metal, to stabilize its thermal, electrical or...

A lens that has one convex surface and the other concave.

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

A method of producing magnified images by x-rays. The specimen is placed close to a point source of x-rays; the...

The elimination of magnetic fields from within a material as that material makes the transition from the normal to...

The ratio of the radiant power transmitted by an object to the incident radiant power.

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

A scale on an optical instrument that indicates the condition of focus. May indicate the distance to the object or diopter...

The production and analysis of spectra with the use of a spectrograph.

A crystal that is characterized by its relatively poor electrical conductance.

A retroreflector that can focus a beam of light, with one planar reflective surface, one spherical and a third that is...

In a visual optical system, the axial distance from the last mechanical surface of the eyepiece to the exit pupil.

Any systemic process that ultimately reassembles all the system's components into their initial alignment, or an arrangement...

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

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

MWIR stands for mid-wave infrared, referring to a specific range of wavelengths within the infrared spectrum. Infrared...

A cathode-ray tube that generates symbols for use in other displays. The tube operates by scanning specific characters on...

A camera equipped with angular scales in altitude and azimuth. The scale readings are imprinted on the film when an exposure...

A spectrophotometer designed for use in the 200- to 380-nm range of the electromagnetic spectrum and equipped with a...

An electron tube whose current flow is affected by the pressure on the gas or vapor contained in the tube.

A detector cooling device in which a gas under high pressure escapes through an expansion valve in the tank; as the escaped...

The optical phenomenon in which right circularly polarized light transmitted by an active medium travels at a different...

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

An instrument for determining the temperature of a hot object by examining the color spectrum of the visible light it gives...

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

Transparent matter that usually is drawn into a cylindrical, pyramidical or conical shape through which light is channeled...

The use of photographs -- motion picture or still -- to establish if a particular event exists.

Angular deviation from the optimum alignment of source to optical waveguide, waveguide to waveguide, or waveguide to...

A vidicon that has a photoconductive surface that can be excited by infrared radiation.

An optical instrument consisting of a well- corrected objective lens or mirror with a light source and or object/image (i.e....

In a straight line. When applied to a lens, it indicates that images of straight lines formed by the lens are not distorted.

Laser powder bed fusion (LPBF) is a type of additive manufacturing (AM) or 3D printing technology that uses a high-power...

A crystal formed by covalent bonds that are generally highly directional by nature. The electric characteristics of these...

Derivative of the half-tone screen process involving the fabrication of a binary pulse-width modulated copy of the...

A transparent crystalline substance that displays the same optical properties (i.e. refractive index) in all directions such...

Two electrodes that shift the electron beam vertically on a cathode-ray tube screen using electrostatic deflection.

The addition to the information signal in communications of redundant bits that enable the originally encoded message to be...

A device for which the output electric field is linearly proportional to the input electric field, and no new wavelengths or...

Concave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These...

Light produced when a metal is bombarded with high-velocity electrons causing small amounts of the metal to vaporize and...

In optical character recognition, the method of dividing a string of characters into separate, distinct characters.

A camera designed with a telecentric optical system and a narrow field of view; the telecentric optical system (placement of...

A measure of the transmittance through an optical medium. Optical density equals the log to the base 10 of the reciprocal of...

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

A computerized token-passing local area network (LAN) configuration adopted by General Motors for real time control over the...

An optical instrument used to isolate a narrow bandwidth of optical radiation using a diffraction grating as the dispersive...

A precision positioning device used to produce rotary motion.

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

The indistinct rainbow that may sometimes be observed outside the distinct primary bow and that has its colors in opposite...

The process whereby a spectacle lens is placed in a frame.

A Risley prism, also known as a Risley prism pair or Risley rotating prism, is an optical device used for controlling the...

A device consisting of two optical systems in which two signals are simultaneously transformed to produce their spectra, and...

The mathematical set of equations showing the relationship between oscillating electric and magnetic fields that are...

A transparent block shaped accurately to reverse curvatures of the components it is used to test. By contacting an...

The science of interfacing surfaces in moving contact, which includes areas such as friction, lubrication and wear.

The distance between the two eye pupils when the observer is viewing distant objects (normal = 62 mm).

An optical crystal that possesses a strong nonlinear dielectric response function to optical radiation. A material with a...

Photometry is the branch of science that deals with the measurement of light, particularly in terms of its intensity and the...

A fiber optic spectrometer is a device used for measuring the spectral content of light. It utilizes optical fibers to...

The finite amount of electrical charge generated in response to incident radiation and transferred from one storage element...

The pattern of lines traced by rectilinear scanning in display systems.

An instrument capable of precise measurements of the Earth's gravity. This permits the detection of small changes in local...

In optics and photonics, "phase" refers to a property of electromagnetic waves, such as light, that describes the position...

A computer hardware unit that generates required functional information on the screen by controlling CRT beam movements or...

A measure of an optical system's ability to produce an image which separates two points or parallel lines on the object. See...

The smallest object that may be seen, measured in terms of the angle subtended by the object measured at the eye. Also...

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

The storage of data as bits in memory by holographic processes. The laser beam is divided into reference and object beams,...

A film applied to a coated or uncoated optical surface primarily for protecting this surface from mechanical abrasion, from...

The measurement of the spectrum bands formed by a spectroscopic sample, based on the differences between the sample and the...

A galvanometric scanner, also known as a galvanometer scanner or galvo scanner, is a type of optical scanning device used to...

Having properties resembling those of light- waves; e.g., the propagation of waves in the television spectrum.

The parameters, relative to polarized light and the Poincaré sphere, that are usually represented as: I, the intensity of...

The slight difference in wavelength of an element's given spectral line observed in comparing different isotopes of that...

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

A metalens, short for "metasurface lens," is a type of optical lens that uses nanostructured materials to manipulate light...

With respect to waveguides, the continuous change in the direction of the axis of the wavelength, during which the axis is...

Piezoelectric motion systems are mechanical systems that utilize piezoelectric materials to generate controlled motion or...

Diffraction efficiency is a measure of how effectively a diffractive optical element (DOE) or diffraction grating directs...

When a block of glass (prism, window, filter, etc.) is placed into a converging light bundle, it increases the physical...

In infrared imaging systems used for mass screening of printed circuit boards or other quality control applications, an...

A crystal capable of being polarized in the reverse direction when an electric field is applied.

Van der Waals forces refer to the attractive or repulsive forces between molecules (or parts of molecules) that arise from...

1. In visual perception, the minimum value of stimulus that can be perceived on the average. 2. In optical detection...

The active control of various aspects (optical element position, airspace thickness, etc.) of an optical system that...

1. A device used in chemistry to compare the colors of solutions held in flat-bottomed tubes and viewed along the length of...

Any of a series of radioactive elements with atomic numbers ranging from 89 to 103.

Ratiometry is a technique used in various scientific fields, particularly in analytical chemistry and biochemistry, to...

First stated by Abbe, condition states that the ratio of input and output angles, from object point to image point, for two...

A shift in the direction of the red in the spectral lines of light which, defined by the relativity theory, will have...

Tip-enhanced Raman scattering (TERS) is a powerful technique that combines Raman spectroscopy with the enhanced spatial...

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

Transmission in different amounts as a function of wavelength, as a result of absorption and scattering, leading to color...

Transparent media which, when placed in front of a light source, change their color as a result of the selective absorption...

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

A device for obtaining very low crosstalk in a crosspoint by arranging two simple switches along different arms of a passive...

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

A pair of telescopes with prismatically erected images, mounted side by side with the eyepieces at the interocular distance...

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

A reflector that exhibits specular reflectance, producing a direct image of its source. Also known as regular reflectance.

An extremely wide emission spectrum generated by the nonlinear effects created when a high peak power from a short-pulse...

The image distortion produced by a panoramic camera with a swinging lens or a swinging mirror in front of a fixed lens. The...

A device used to view microfilmed documents where the image on film is projected, in magnified form, onto a rear projection...

In semiconductor physics, the term bandgap refers to the energy range in a material where no electronic states are allowed....

Any isolated wave that propagates without dispersion of energy. Specifically to photonics, an ultrashort pulse of laser...

A coating made up of many layers of material having alternating high and low refractive index. In this way, it is possible...

The process by which a substance, usually a solid, attracts and retains on its surface the molecules of another substance.

In a laser, the fraction of plasma volume used by a particular transverse mode of oscillation, a determinant of the gain...

In physics, momentum transfer is the amount of momentum transferred from one particle to another during particle collision...

A small mass spectrometer, with a limited mass range, equipped with an analyzer to generate a cycloidal-path beam of the...

A compound prism composed of two 30° prisms, one of which is partially coated with a suitable opaque metal of high...

The arc formed when the rare gas xenon is excited electrically and emits a brilliant white light. Xenon is used to fill...

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

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

A series of flanges or other conducting surfaces, usually metal, attached to an electronic device to transmit and dissipate...

The material that has the lowest possible constant melting point of any possible combination of the same components.

A graphic representation of a distribution function such as frequency by means of rectangles whose widths represent the...

A well plate, also known as a microplate or microtiter plate, is a flat plate with multiple small wells or depressions...

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

An optical recording technique that uses light source(s), a beamsplitting cube, light detector(s) and an optical fiber...

A device used to scan, with a small, intensely bright spot, portions of a picture surface and to transform the original...

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

The acoustical holographic process in which the hologram consists of slight elevations in a liquid surface, in the areas of...

Optical elements that use diffraction to control wavefronts. Diffractive optical elements include diffraction gratings,...

An electrochemical process of metal fabrication using an electrolyte, an anode to supply the metal, and a control of the...

An ophthalmic instrument used to measure the magnitude and direction of the maximum and minimum powers of a spectacle lens,...

The use of thin flexible glass or plastic fibers as wave guides — or "light pipes" — to channel light from one...

Also referred to as a bulb. The glass housing that encloses an incandescent source, or the glass or metal housing that...

Light transmission involving no scatter.

A technique that uses the passage of an electrical current through a recording medium to produce a permanent image on that...

In optics, the Pockels effect refers to the phenomenon where the refractive index of a material changes in response to an...

An aerial reconnaissance system that can transmit, in near real time, image data recorded by IR and visual-spectrum sensors,...

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

The effect produced by electrical charges or fields alone, without interaction with magnetic influence.

Histochemical staining is a laboratory technique used in biology and medicine to visualize specific chemical components...

Full width half maximum (FWHM) is a measure of the extent of a function. Given by the difference between the two extreme...

That characteristic which makes a weapon system less visible to radar, optical, acousto-optic, infrared and other military...

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

An imaging process in which the single opening of a simple pinhole camera is replaced with many openings called,...

A filter, partially opaque to near-ultraviolet, visible and infrared radiation, that may be made by exposing and processing...

A photovoltaic device that consists of multiple p-n junctions to produce a greater efficiency when in use than that of...

In analysis, a reference spectrum, having predetermined wavelengths, that is used to determine the wavelengths of another...

A physical constraint, often a lens retainer, that limits the diameter of the axial light bundle allowed to pass through a...

Transparent glassy and or crystalline structured materials engineered from inorganic, non-metallic materials via various...

In a laser, the voltage necessary to initiate electrical discharge, somewhat higher than that needed to sustain it.

In fiber optic communications, a light source whose beam can be modulated and sent along an optical fiber, and the...

A straight line, real or imaginary, passing through a body and indicating its center; a line so positioned that various...

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

Characteristic of a reflector that reflects light along a different line or lines than that of the incident ray.

An optical material used in place of crown glass to produce lenses with extraordinary correction of chromatic aberrations....

Hyperspectral imaging is an advanced imaging technique that captures and processes information from across the...

The method of disintegrating the substance of the cathode by bombarding it with ions and depositing it on another electrode...

The product of Avogadro's constant and the electrical charge of an electron; thus, the electrical charge carried by 1 gmol...

A self-interference effect that generates random patterns; secondary speckle pattern (SSP) typically occurs in diffuse...

The diffraction of a particle by a standing lightwave.

The transform defining that, if a reference beam is a divergent spherical wavefront, then the reconstructed image will be...

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

A term used to describe a photograph, film or television picture where the values for black and white areas are at or near...

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

Abbreviated TEA CO2 laser. A gas laser that provides shorter pulses and higher peak powers than conventional CO2 lasers. The...

A method of growing single crystals in which atoms and molecules from gaseous organic compounds interact and form a layer on...

A phenomenon that causes the details in an image to appear at a spatial frequency higher than that at which the contrast...

A method of evaluating image quality whereby a large number of rays are traced through a lens from a single object point,...

A type of pyroelectric detector with favorable qualities of linearity, sensitivity and spectral responsivity used in FTIR...

A laser effect used especially for laser light shows. Lumia are created by placing a distorting medium such as rippled glass...

A very hard, highly transparent coating based on forms of carbon, used to protect optical components from abrasion and...

An optical system that uses refraction to form an image.

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°...

The control of an instrument or electrical circuit by the current produced by varying radiation incident to a photoelectric...

An instrument designed to give precise and rapid detection of changes in tumor growth as well as the location of small...

Category inclusive of all radiation that is incited electronically, except laser radiation, as a function of the application...

A film of material that exhibits varying conductivity based upon its absorption of varying amounts of photon radiation.

In optics, the mechanical tension, compression or shear in optical glass due to internal stress caused by improper cooling...

A spectrograph in which the flux density transmitted through the entrance aperture is regulated by an optical wedge or...

For light incident on a plane boundary between two regions having different refractive indices, the angle of incidence at...

An antireflection coating (AR coating) is a thin film or coating applied to optical surfaces, such as lenses or windows, to...

The area of optics in which quantum theory is used to describe light in discrete units or "quanta" of energy known as...

A reflection grating is an optical component that consists of a series of closely spaced, parallel reflecting surfaces or...

A Pockels cell, also known as an electro-optic modulator, is an optical device used to control the polarization of light by...

A method of polishing an aspheric surface by mechanically distorting the optic while polishing the surface to a perfect...

A spectrophotometer having a pair of identical collimators with two Glan polarizing prisms, one fixed in azimuth and the...

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

That process by which radiation spontaneously emitted by a volume of optical materials is resonantly reabsorbed within the...

A contraction for "texture element." A base unit used in computer graphics that defines the surface of three-dimensional...

A device consisting of an airtight quartz tube that holds the material to be analyzed. When a high-frequency electrostatic...

High harmonic generation (HHG) refers to a nonlinear optical process in which intense laser light interacts with a gaseous...

Electromagnetic energy that is capable of producing photochemical activity.

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

Phase matching is a crucial concept in the field of optics, particularly in nonlinear optics and the generation of coherent...

A group of single emitter laser diodes, usually arranged vertically or horizontally with respect to each other. The power...

The technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon. The...

The area of optics that deals with the propagation of Gaussian laser beams in free space, or any general medium - i.e....

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

An isotope of cesium that emits negative beta particles and has a half-life of 2.19 years; its applications include...

A ray that travels from one point to another without being reflected or refracted.

This term literally means "to lag behind.'' It is quite often used to describe the residual effect that remains after...

A circular optical wedge (prism of small refracting angle) mounted to be rotated in the path of light rays to divert the...

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

The distribution of energy about the image of a point source in the focal plane of an optical system.

A two-flux theory in which the radiation is assumed to be composed of two oppositely directed radiation fluxes through a...

Sputtering equipment is machinery used in the process of physical vapor deposition (PVD), specifically sputtering....

An instrument designed to measure the refractive power and range of accommodation of the eye. See ophthalmic instruments.

Plasmonics is a field of science and technology that focuses on the interaction between electromagnetic radiation and free...

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

A micro-ring resonator is a compact optical device that utilizes the resonant behavior of light within a small ring-shaped...

A sensing or image-forming detector that serves to convert infrared rays into visible signals for communication purposes....

A semispherical or conical lens created directly on the core of an optical fiber to focus light from a laser into the fiber...

Any device that is used to sense and measure light. See exposure meter; photoelectric exposure meter; photoelectric...

A device that prevents electrons from a saturated pixel in a CCD imaging device from spilling into an adjacent pixel. The...

A photoelectric photometer used to measure the reflectance of a surface.

A microscope that uses a flying spot scanner, directed through the eyepiece, as a light source to determine the features of...

A device that holds a number of filters and allows the filter with the desired characteristics to be rotated into an optical...

A light beam whose electric vectors all vibrate in a single fixed plane.

Equipment that supports microscopic live-cell imaging by managing the gas, media perfusion, temperature and other factors to...

A lens aberration that results in the tangential and sagittal image planes being separated axially.

In gradient index optics, a gradient profile in which the index varies in a direction perpendicular to the optical axis....

FMCW lidar stands for frequency-modulated continuous wave lidar. It is a type of lidar (light detection and ranging)...

The measurement of surface temperature by a thermograph that forms a pattern of the heat radiated by the surface on a...

In a solid-state laser, the material (Nd:YAG, Nd:glass, ruby) in which lasing action takes place.

The butt (edge to edge) splice of two pieces of film produced by a heat splicer that melts the edges together; used in...

A type of transversely excited laser with a uniform arc-free discharge of large cross-sectional area that can be scaled to...

Average wavelength usually determined for light-transmitting devices by taking a weighted average for each wavelength of the...

Also known as real holographic image. The indistinct, highly distorted image produced on the side of the hologram closest to...

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

A time-to-amplitude converter (TAC) is an electronic circuit that converts a time interval between two events into an...

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

A lens used in the optical testing of an aspheric surface. It converts a spherical wavefront into one that precisely matches...

The point function in a wave equation that represents the amplitude.

A reticle carrying patterns of various forms that can be rotated in an optical beam to cause variations in the intensity of...

Device which measures the index of refraction of glass as well as the dispersion over visible range.

A solar cell that uses a thermoelectric converter, consisting of two sheets of metal with a semiconductor sandwiched between...

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

Potential hazards to a system's application and installation, including temperature variations, chemical reactivity,...

An instrument designed for laser technology that is used to extract single pulses from the laser and transmit a portion of...

An infrared device used in satellites and rockets to determine a heat horizon for the Earth at altitudes (above 200 miles)...

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

The development of a transverse electric field in a solid material when it carries an electric current and is placed in a...

A vacuum gauge designed to measure very high degrees of vacuum by thermal conduction.

Topology is a branch of mathematics that focuses on the properties of space that are preserved under continuous...

Optical fibers fused together to form a solid, vacuum-tight assembly in the form of a slab or rod. Discs or rectangular...

The instrument used to collect thermal radiation information on an object by scanning. It consists basically of a detector,...

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

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

Also known as cathode-ray tube grid or shield. A cylindrically shaped electrode that, containing the cathode of a...

A crystal, glass, or quartz slicing and cutting machine is a specialized piece of equipment used in the manufacturing...

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

Contains the light or beam path within a laser device. The oscillator uses reflective optical components that are oriented...

An interface in an optical network that permits an optical signal to pass without changing the optical signal to an...

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

The representation of arbitrary functions as the superposition of sinusoidal functions whereby the representations...

A type of flat panel display made up of a layer of gas between two glass plates. The glass is coated with parallel...

A semiconductor diode operating in either a coherent or incoherent mode that is used as a near-infrared or visible source in...

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

Color sensitivity extended to cover the entire visible spectrum out to the red.

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

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

Approximation of a system of thermal equilibrium formed by the distribution of the kinetic energies of electrons in a gas...

The action of a biological system responding to a single or multiple coherent particles of light produced from a laser...

A method of graphical ray tracing through a boundary surface dividing two media of differing indices of refraction.

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

Dewetting is a phenomenon in materials science and physics where a thin film or coating spontaneously undergoes a process of...

A metal coil or coils wrapped around the outside of the neck of a cathode-ray tube. Current passing through the coils...

A monitoring technique used to measure the oxygen saturation levels in the brains of patients, commonly in operating room...

A term denoting the magnitude and direction of the magnetic field associated with an electromagnetic wave when describing...

In an avalanche photodiode, the gain multiplied by the signal frequency in MHz.

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...

The photographic image of a thin specimen having a radioactive isotope that, formed through contact between the specimen and...

A Dammann grating is a type of diffractive optical element (DOE) used to create an array of equally spaced,...

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

Autofluorescence refers to the natural emission of fluorescence exhibited by certain biological structures or molecules when...

A measurement device used to study the structure of matter using the diffraction of electromagnetic radiation.

In an astigmatic grating, the image of the entrance slit located at the primary focus.

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...

An electron-beam tube with power-handling capability that is essentially based on controlled electron beams. Its control and...

A confocal resonator, also known as a confocal cavity or confocal laser resonator, is a type of optical resonator...

Computation of tristimulus values by integrating or summing, over the visible wavelength region, the product of the relative...

A transformer that is designed to regulate the amount of current that passes through an electron tube's filament.

That term pertaining to the spectral region that can be perceived by the eye.

Also known as an anticathode. An electrode or electrode section that is focused upon by an electron beam and that emits...

An analytical technique used to determine, identify and localize impending malfunctions. It is based upon quantitative and...

The Shack-Hartmann wavefront sensor is an optical device used for measuring the wavefront aberrations of an optical system....

A lens that is implanted within the eye to replace the eye lens, which has been removed because of cataract or other defect.

Linear receive optics typically refers to the optical components and systems used in the reception (detection) of linearly...

The illusory appearance of a light or dark band at a line of brightness contrast that enhances the edge between the two...

A photomultiplier tube (PMT) is a highly sensitive vacuum tube that detects and amplifies low levels of light. It is widely...

An acronym for radioactive detection, identification and computation. The term refers to the detection and measurement of...

Laser light show effects equipment including optics and mechanical devices that reflect, position or distort the laser beam,...

Time-correlated single photon counting (TCSPC) is a technique used in photon counting applications, particularly in the...

A subtractive colorimeter that expresses a liquid's or object's color as a combination of three colors. These colors are...

In microscopy, a calibrated scale on a slide that may be viewed to determine the exact magnification factor of the...

The product of exposure time and irradiance or illuminance.

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

A physical stop that is conjugate to the entrance pupil and is used primarily to reduce diffraction effects at longer...

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

A compact, folded version of a Dove prism, made of high-index glass with a silvered base and used for image rotation.

An optical system that is corrected for distortion and spherical aberration and therefore forms the image of a straight line...

A method of predicting the nonlinear optical effects exhibited by different molecules without synthesizing the molecules...

A spectrometer equipped with polarizing prisms and retardation plates that is used in the analysis of elliptically polarized...

A term applied to an electric charge image in a camera tube that remains for a period of a few frames after its initial...

An inspection device in which the profile of a mechanical part is projected onto a ground-glass screen at a precisely known...

A lamp that yields a nonluminous flame; used in the spectroscopic analysis of radiation emitted by a substance placed in the...

In an optical data storage system, denoting the optical head's ability both to record information and to detect it for...

A type of modulation spectroscopy that measures spectral reflectance or transmittance changes induced by applying a...

Gain-switching is a technique used in lasers to generate short pulses of light by modulating the gain of the laser medium....

A mask-alignment microscope used to produce and inspect microcircuits in the electronics industry. It provides flat-field,...

A laser diode in which the beam is confined to the region of the active layer with gain high enough to accomplish such...

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

A detector's ability to sense an object on the opposite side of a thin but opaque barrier such as cardboard.

Refers to the variety of techniques that use the interference pattern produced by laser light diffusely reflected by an...

A scintillation detector is a radiation detection device that utilizes scintillation crystals to detect and measure ionizing...

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

An instrument for detecting and analyzing repetitive signals. Using a fixed time delay or "gate," the input signal...

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

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

Pictorial information processing in which the processed picture shows a family of equidensity lines or bands coded with...

In image processing, the mathematical relationships that link pixel brightnesses of input images to those of output images...

Power modulation refers to the intentional variation of power levels in a signal, often in the context of electronic...

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

The region of the electromagnetic spectrum from 280 to 320 nm.

The partial differential equations for the spatial and time dependence of electric and magnetic fields inside a...

the photography of very close, and typically small objects with a magnification of approximately 1:1

A metabolite is any small molecule that is a product of metabolism, the chemical processes that occur within living...

A device that detects radiation by utilizing the influence of light in forming an electrical signal. It may be a phototube;...

Generation of an acoustical signal by a sample exposed to modulated light.

Refers to a display or screen that is illuminated from behind; the light is transmitted as opposed to reflected.

The study of crystal growth from the molten stage utilizing a holographic system wherein interferometric techniques record...

A plot showing how the response (ability to detect a signal) varies with wavelength. D(l).

A multidimensional array of values that is commonly used in programming to describe a time series of image data. Each...

The effect whereby a light beam is deflected by a birefringent prism when its polarization is changed by voltage applied to...

A common technique in microscopy, oblique illumination is one in which the object is illuminated by a light source that is...

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

Ratio between map or photo linear distance and the actual ground dimensions represented.

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

A type of wide-angle lens that has an angular field above 140° and that exhibits barrel distortion. The most commonly...

The determination of the relative phase shift of an image as a function of frequency. A phase change of 180° with...

The light formed by visible radiation that, in traveling from light source to object, undergoes one or more reflections. In...

A mid-infrared camera is a type of imaging device designed to capture images in the mid-infrared (mid-IR) spectral range,...

A factor of an equation of the Faraday effect, which is the rotation of the plane of light polarization by transparent...

The law stating that the brightness of an object that is examined through a slotted disc, rotating over a critical...

A process used to control thickness and parallelism precisely during the production of plane-parallel plates. Elements are...

A coarse diffraction grating that is used to form a scale of intensities to determine the relative magnitudes of stars. The...

Quantum-enhanced metrology refers to the use of quantum mechanics principles and techniques to enhance the precision and...

In image processing and elsewhere, generally an adjective to describe an assembly-line arrangement for performing a task....

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

Laser optics refers to a broad category of optical components and systems designed for manipulating and controlling laser...

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

The range of image distances that corresponds to the range of object distances covered by the depth of field.

A device designed to measure crystal properties by analysis of crystal diffraction.

Technique using functional optical microscope with the addition of a coherent source collinear with the image path. The...

A television system that uses a slow rate of horizontal scanning to increase its reproduction and transmittance accuracy of...

A network interface card (NIC), also known as a network adapter or LAN adapter, is a hardware component that allows...

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

A television receiver that receives the signals generated by a television camera directly, or remotely through a radio...

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

A statistical means of characterizing the failure of a fiber or device as related to strain or time. Results are plotted on...

A device, consisting of a diode activated by an interference pulse, that is designed to minimize the white spots on a...

A device similar to distributed feedback lasers in construction and operation, but in which the period grating that produces...

In the context of optics and lasers, a transverse mode refers to a specific spatial pattern of the electric field within the...

1. Synonymous with radioactivity. The intensity of a radioactive source illustrated as the number of atoms disintegrating in...

An adaptation by Philips and Sony of their audio compact disc technology for optical disc data storage and retrieval....

Activity of a radionuclide having one spontaneous nuclear transition per second.

A term used to describe a nondirectionally diffusing surface that, when illuminated, appears equally bright from all angles....

The processing of an image or portion of an image by transform coding and analysis. Fourier, Hadamand, Kronecker and...

Array used in coded-aperture imaging experiments with two-beam CO2 lasers that provide an artifact-free process, faithful...

A process of forming ions within a given molecular species by incident laser light. The molecular species may remain intact,...

A standard direct-readout vidicon tube linked by fiber optics to an intensifier for increased sensitivity.

A photosensitive device used to optically scan and read character data (numbers, letters etc.) and input this data into a...

The changing of the kinetic energy of a mobile electron into radiant energy, as in formation of x-rays.

A refractometer that has a greater resolving power than a standard refractometer, and that uses a pentagonal prism to split...

A sapphire window refers to a transparent optical component made from sapphire crystal. Sapphire is a single-crystal form of...

The description of the refractive index along a fiber diameter.

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 device for automatic exposure control in which a motor-driven diaphragm adjusts the aperture in response to a signal from...

An astronomical body that emits radiation concentrated by a strong magnetic field into two beams that rotate, giving a...

The path of a given point on a wavefront. One of the radii of a wave of light that indicates the direction of light travel.

Plot of spectral luminous efficiency vs. wavelength.

Collaborative Robot (Cobot): Unlike traditional autonomous robots, which usually work by themselves, a collaborative robot...

A circuit incorporated into counter systems that records only pulses that have amplitudes between two preselected limits.

The method of acquiring characteristic x-ray spectra from microscopic samples by use of the combination of a scanning...

A collimator having, at one end of a tube, an objective lens, and at the other, a reticle with a pair of spaced lines...

In holography, the beam of light that is directed from the beamsplitter to the recording medium, where it interferes with...

The spectral transmission window in silica-based fibers between 830 and 850 nm.

The ionization that occurs in gas affected by the action of radiation quanta.

Photolithography is a key process in the manufacturing of semiconductor devices, integrated circuits, and...

Two microscopes that are coupled on a common stand, the two images being projected side by side in the field of view of a...

An electron tube containing neon gas that uses the transmission of an electric current through the gas to ionize the neon...

An inorganic compound, yellow to orange in color, that fluoresces strongly enough when bombarded by a high-current-density...

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

A cathode that emits electrons, not with the influence of heat radiation, but by means of a high-voltage gradient at its...

A series of capacitors and inductors connected to the flashlamp in a pumped Nd:YAG laser system in order to regulate the...

A mass spectrometer used to detect ions formed by photo- and charge-exchange ionization of gases, such as those in the lunar...

The basic process of color photography whereby colors are subtracted from white light by means of filters, making all colors...

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

When a lens system with a circular aperture is free of aberrations, the image of a point object will appear as a disc of...

The unit solid angle subtended at the center of a sphere by an area on its surface equivalent to the square of the radius;...

An interference filter in which a very thin metal foil with a periodic array of square holes (inductive mesh) or a thin...

Electromagnetic energy is transmitted in the form of a sinusoidal wave. The wavelength is the physical distance covered by...

A high-resolution imaging instrument that can detect and measure the positions of individual atoms on the surface of a...

A spectrum of component wavelengths whose values are separate from each other.

Return of radiation by a surface, without change in wavelength. The reflection may be specular, from a smooth surface;...

Colorless crystals used in photoelectric cells and for photosensitive material in cathodes.

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

A type of refractometer designed to measure the refractive indices of liquids. A section of the instrument is immersed into...

When light is transmitted through matter, part of the light is scattered in random directions. A small part of the scattered...

A crystalline semiconductor material that transmits in the infrared.

The green line, in the spectrum of the aurora borealis, that has a wavelength of 5577 Å; it is caused by a forbidden...

A wave whose surfaces of constant phase are infinite parallel planes normal to the direction of propagation.

A lithography method that allows the transfer of fine-pitch gratings from a phase mask into photoresist. The exposure takes...

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

A fiber optic end plate constructed by drawing a bundle of parallel fibers embedded in glass and cutting it into thin...

A system that transmits and receives identification codes to facilitate the discrimination between enemy and friend in a...

A material in which the refractive index varies according to changes in the light to which it is exposed. Lithium niobate is...

The simultaneous occurrence of direct and diffuse transmission.

The field of view seen through some types of coincidence rangefinders. It is formed by the juxtaposition of opposite halves...

With respect to crystals, having three mutually rectangular axes, only two of which are equal.

Condition in which two stimuli appear to match in color to a specified observer, or in which two objects appear to match in...

An instrument devised by Nichols and Hull for use in the measurement of radiation pressure. The device has two small...

Two plane mirrors that are not wholly located in the same plane. When light from a point source or slit reflects from the...

Optical coherence tomography (OCT) is an imaging technique used in medical diagnostics and biomedical research to obtain...

One of the electrodes used to focus the electron beam of a cathode-ray tube. As the electrode's voltage is changed, its...

The process in which the electron beam of a cathode-ray tube varies in intensity in accordance with the magnitude of the...

An alphanumeric display formed by a layer of liquid crystal material sandwiched between two sheets of glass; a transparent...

Two essential pieces of equipment used in connection with the microfilming process: a camera capable of producing, on film,...

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

A device used in solar systems to direct mirror-reflected sunlight to a heat absorber and heat-driven engine, which turns a...

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

The relative power emitted by a source as a function of wavelength. It determines the color-rendering properties of the...

A computer-generated hologram (CGH) is a holographic image produced using computational methods and algorithms, rather than...

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

An imaging system designed to highlight small deviations in a planar reflective object such as a mirror. The system can be...

The maximum to minimum range of temperature, pressure, humidity, vibration and biological conditions under which an optical...

The organ of vision or light sensitivity.

An instrument that produces an intense, tightly focused beam of ions to stimulate emissions from a minute section of a...

Also known as roof prism. A type of prism designed by G.B. Amici. It consists of a roof edge produced upon the long...

A filter that allows heat radiation from an incident beam to pass without absorption or reflection.

The electrical power used to stimulate any light source. Power supplies may be step-up or step-down transformers; rectifiers...

A ray of light that falls upon or strikes a surface of an object such as a lens. It is said to be incident to the surface.

An erecting prism that inverts and reverses the image. It displaces the optical axis but does not deviate it.

1. In optics, the ability of a lens system to reproduce the points, lines and surfaces in an object as separate entities in...

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

Decibels referenced to one milliwatt; often used to specify power ratings for semiconductor diode lasers.

A 2-million W, 2.7-µm-wavelength hydrogen-fluoride laser used as a directed energy weapon.

A crystal that is devoid of any mosaic structure and that can reflect x-rays, relative to the Darwin-Ewald-Prins law.

Backscatter refers to the phenomenon in which radiation or waves are scattered backward, opposite to the direction of the...

Photoresist is a light-sensitive material used in photolithography processes, particularly in the fabrication of...

Optical elements that have been coated with one or more layers of dielectric, or metallic material. These coatings serve to...

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

1. A lens situated at or near the plane of an internal image to project the aperture of a previous objective or erector upon...

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

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

A device that provides means for accurately moving minuscule tools over the surface of a microscopic object. The motion...

In optics, a motion controller refers to a device or system that precisely controls the movement of optical components, such...

One of a class of crystalline substances belonging to triclinic, monoclinic and orthorhombic systems that have two optic...

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

Total internal reflection fluorescence (TIRF) microscopy is an advanced fluorescence microscopy technique that leverages the...

A quantitative measurement of the coherence of a light source; equal to the visibility (V) of the fringes of a two-beam...

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

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

The theorem stating that, when the sampling period in a recorded sample hologram is matched to the object spectrum, the...

In a crystalline substance, the spectral range of states of energy that contains the crystal's binding valence electrons.

Fluorescent proteins are proteins that exhibit the property of fluorescence, which is the ability to absorb light at a...

The phenomenon observed by A.H. Compton in 1923 -- that some scattered radiation possesses a longer wavelength and...

A perfectly diffusing surface; the intensity of the light emanating in a given direction from any small surface component is...

Correction of an optical system at four separate wavelengths. This correction, longitudinal and lateral, is possible with...

A CCD device in which a solid-state electron multiplying register has been added to the end of the normal serial register....

1. The reduction in the developable density of a photographic emulsion that has been extremely overexposed. 2. In a laser...

A crystalline semiconductor alloy used as the light confinement layer in both single- and double-heterostructure diode...

Brightfield refers to a type of microscopy and imaging technique in which the specimen is illuminated with a white light...

An instrument for measuring the brightness (luminance) of a scene. It may be a spot meter, covering an area of a degree or...

In remote sensing technology, this represents the intensity of energy flow in the direction of wave propagation.

Pertaining to the possession of photoelectric characteristics as a result of the properties of the true crystal and not of...

A grating that specularly reflects the specified long radiation wavelengths and diffracts the shorter wavelengths off in...

Sets of lenses (positive, negative and cylindrical) usually mounted in circular rims suitable for slipping into trial...

The number of electrons that each pixel of a charge-coupled device can hold without overflowing and causing blooming.

In the SI system, prefix meaning 10-24. (y).

An infrared detector in which radiation passes through a doped germanium crystal, creating a voltage drop that can be...

The production of visible light by infrared radiation whereby the light is produced by heat and not by any direct change in...

A photomicrographic recording technique that utilizes dark-field illumination to render an image of an object having a...

A type of electroluminescent display that will record and maintain an irradiated image on its phosphor screen, provided a DC...

Metrology is the science and practice of measurement. It encompasses the theoretical and practical aspects of measurement,...

On a chromaticity diagram, the line on which fall the chromaticities of the pure spectrum colors.

Simulation of radiative transfer in which each photon is generated by a source and its path through the medium is...

The phenomenon in which alkali metals are transparent to ultraviolet radiation.

An optical instrument containing a gimballed sighting telescope, used to measure angular relationships in horizontal and...

An infrared transmitting material used in the production of fluoride glasses for optical fibers.

An edge-emitting light-emitting diode is a type of LED structure where light emission occurs primarily along the edge of the...

The term light field refers to the spatial distribution of light rays traveling in all directions through a given space. It...

Modified chemical vapor deposition (MCVD) is a technique used in the fabrication of optical fibers. It is a specialized form...

In a CD-ROM disc, the reflective area between nonreflective pits representing a binary-language "off'' as opposed to...

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

A solid with a structure that exhibits a basically symmetrical and geometrical arrangement. A crystal may already possess...

Liquid crystals are a state of matter that exhibits properties intermediate between those of conventional liquids and solid...

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

A fiber optic transceiver, often simply referred to as an "optical transceiver," is a device used in fiber optic...

An optical storage product that can be used for playback only.

In chemistry, a device in which a chemical reaction takes place. In electronics, a device that introduces reactance into a...

1. The use of an electronic microdensitometer to measure points of equal density on a photographic deposit. 2. A technique...

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

A series of permanent holograms in dichromated gelatin formed by opening total page-composer apertures and setting a point...

A CMOS camera refers to an imaging device that employs a complementary metal-oxide-semiconductor (CMOS) image sensor to...

An instrument incorporating an infrared detector assembly, used to analyze carbon dioxide gases and in medical applications...

A spectral signature, in the context of remote sensing and spectroscopy, refers to the unique pattern or characteristic...

The transition cross section constant coefficient which defines the transition probability of absorption from ground to a...

The determination of the temperature of a source by the detection of its incandescent brightness.

Irregular propagation of a wave due to variations in the medium's density or refractive index.

In the context of electronics and semiconductor manufacturing, a wafer refers to a thin, flat disk or substrate made of a...

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

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

The disordered, glassy solid state of a substance, as distinguished from the highly ordered crystalline solid state....

Contour mapping technique that involves positioning a grating close to an object and observing its shadow on the object...

With relation to the equivalent beam candlepower of a searchlight, the candlepower of a bare source that would produce the...

An optical system used to collect infrared energy from a scene using scanning optics with a point or line detector, as...

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

Use of a photoelectric receiver to sense an object's presence by detecting a small amount of the emitter's light that is...

An instrument for measuring reflectance.

A technique in which a beam of x-rays is directed against a crystal, the atoms of which, because of their lattice...

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

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

The study of radioactive substances and high-energy radiations such as x-rays and g-rays.

Recombination of only the light that is correctly dispersed by the first stage of a polychromator through its wide...

The visual perception of contrasting forms is more difficult if the forms have the same luminance but different...

The amount of x-rays used to penetrate and diffuse a target sample undergoing electron-probe microanalysis.

A type of photoconductive detector in which germanium, usually doped with boron, gallium and indium, serves as a...

In positioning, rotation about the line of sight or direction of travel.

Photoplethysmography (PPG) is a non-invasive optical technique used to detect changes in blood volume in tissues. It...

The point at which short-wavelength transmission is cut off.

The object distance at which the eye is focused with the eye lens in a neutral or relaxed state.

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

Optical fiber channel characterization scheme based on three assumptions; the discrete mode spectrum can be replaced by a...

Best point of focus for an image in a beam of light at the smallest cross section of the beam.

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

Nanoparticle photonic resonator absorption microscopy is a microscopy technique that combines the principles of photonic...

Gallium nitride-based light-emitting diodes (GaN-based LEDs) are semiconductor devices that emit light when an electric...

The ability of an optical system to make an object appear larger. An optical element or optical system causing an object to...

A microscope that uses an extremely fine x-ray focal point to produce an enlarged photographic image of a sample. Also known...

Volumetric imaging refers to the capture, visualization, and analysis of three-dimensional (3D) information from a volume of...

The image of the sun produced by a spectroheliograph.

Conduction of an electric current through a chemical compound in its natural state, solution or as a molten, to decompose...

A transistor that uses an electro-luminescent source, a transparent base and a photoelectric collector.

A device in which the functions of optical detector and emitter are combined.

A contraction of binary digit; the fundamental unit of digital computing, a bit is either 1 or 0, expressing the binary...

A laser system consisting of a planar PN junction within a single crystal of gallium arsenide. The pair of parallel,...

The law stating that the illuminance (or irradiance) from a point source varies as the inverse square of the distance...

In optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it....

A small object that behaves as a whole unit or entity in terms of it's transport and it's properties, as opposed to an...

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...

Microscopic investigation of two-dimensional areas of a three-dimensional object that can be quantitatively evaluated by...

The principle that states that optical instrumentation cannot increase the radiance of a source; the radiance of an image...

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

A device that converts alternating voltage to direct voltage, while at the same time increasing its amplitude.

A source that attempts to create the characteristics of an ideal blackbody. It consists of a cavity, generally spherical,...

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

With respect to color photography, the measurement of the way the color film modulates the radiant flux in the optical...

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

1. A strainmeter capable of measuring the change in the relationship between two reference points, provided that the points...

E.I. duPont's trade name for a polyester film. The most practical beamsplitter for use beyond the 15-µm wavelength...

Recombinase polymerase amplification (RPA) is a molecular biology technique used to rapidly amplify specific DNA or RNA...

Laser marking is a process in which a laser beam is used to mark or engrave a surface by altering its properties or...

With respect to a chromaticity diagram, this is the locus of points that represent the chromaticities of blackbodies...

The discernment of depth or apparent difference in distance that causes the object to stand out from its background because...

A two-electrode, radiation-sensitive junction formed in a semiconductor material in which the reverse current varies with...

A mechanical shutter that has had its timing escapement replaced with an electronic timing circuit. This circuit allows a...

The maximum rate at which temporally disjunct optical signals can be produced or detected.

A light source that produces an equal-energy spectrum.

A halogen lamp, also known as a tungsten halogen, quartz-halogen, or quartz iodine lamp, is an incandescent lamp that uses a...

The mean square difference in refractive index for two separate points in space.

Interaction of a magnetic field with a photoconductive substance exposed to light to create a potential difference.

A device, also called a fluorescence lifetime instrument, that measures decay curves of fluorescing samples. It generally...

An antigen is any substance that is capable of triggering an immune response in an organism. Antigens are typically proteins...

A method of sensing by transmitting energy from the sensor and detecting the energy after it has been reflected by the...

A test similar to the Knoop hardness test, but used for fractured material. The indenter is a square-based pyramid-shaped...

An electro-optic system using, in general form, an evacuated glass envelope with a semitransparent photocathode at one end...

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

An imaginary line between the object, through the nodal point of the eye, and the fovea, or point of finest retinal acuity.

A two-electrode device with an anode and a cathode that passes current in only one direction. It may be designed as an...

1. A localized fracture at the end of a cleaved optical fiber or on a glass surface. 2. An integrated circuit.

A display format consisting of small light-emitting elements arranged as a two-dimensional array. Various elements are...

Property of a surface which, because of directional reflection, is responsible for the degree to which reflected highlights...

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

Variations in a signal passing through an optical fiber caused by the effect on the pulse of the fiber's material and mode...

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

A device used to accelerate the electrons in a free-electron laser by channeling microwave energy into waveguide cavity...

A refracting telescope that uses a prism to bend the line of sight 90°.

The capacity of a chiral substance such as a crystal or molecule to rotate the plane of polarized light that is transmitted...

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

The simultaneous exposure of two holographic plates with emulsions facing the object. After deformation, a second pair of...

The process by which laser emission is used in measuring fluid velocity and, more specifically, the detection of air and...

A direct reading spectrograph having a photomultiplier assembly in place of a photographic plate. The output from the...

A direct-vision prism made in one piece that can be used only in parallel light.

A Kerr soliton refers to a specific type of soliton, a self-reinforcing wave packet, that arises in nonlinear optical...

The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or...

An OLED display that has an integrated electronic backplane as its substrate. Active-matrix OLED displays use at least two...

The scanning of a region in a given sequence of slender, straight parallel strips.

A contact tip made of artificial sapphire (AlO2) that allows surgeons to use laser power to cut and coagulate tissue...

The study of chemical reactions stimulated by the properties of light.

Oscilloscope electronic circuit that produces an output pulse whose pulse width is determined by the time that the output...

A sensitometer that utilizes an electronic flashtube or a photoflash lamp as both the light source and the shutter for...

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

A specific type of filter designed to reduce the amount of light scattered by reflections from the edges of optical...

A semiconductor diode that exhibits change in capacitance with a change in applied voltage; used as a voltage-variable...

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

Decrease in cosmic ray activity that is observed approximately 24 hours after a solar flare, attributed to a shielding...

The change in the refractive index of a material under the influence of an electrical field.

A machine vision system is an integrated combination of hardware and software components designed to capture, process, and...

The luminous trace formed on the cathode-ray tube screen by the motion of the electron beam.

With respect to a traveling plane wave at a known frequency, the space rate of decrease of phase of a field component in the...

Temperature of the blackbody having a spectral power distribution approximately proportional to the test source at all...

A dome-shaped structure used for some optical instruments in place of a flat window. The transparent material should be of...

The analysis of metal structure using an optical or electron microscope, generally with a camera, to record observations.

An exposure meter that indicates the amount of light reflected from the subject of interest.

A furnace, generally electrically heated, with a control system capable of following a cam by which the temperature can be...

The use of head-mounted displays and body-operated remote actuators to control distant machinery. Provides a virtual...

The ratio between the object distance and the image distance measured along the principal axis of a lens or mirror. An...

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

The photographing of a scene from positions corresponding to the locations of both eyes. A viewing device is used to present...

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

A number that indicates the magnitude of the shift in a solid of positive and negative charges in opposite directions when a...

Elastic deformation of a dielectric caused by volume force when the dielectric is placed in an inhomogeneous electric field.

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

The production of an image on a magnetic film that is exposed to infrared radiation and heated to a point above Curie...

A type of change in the energy levels of molecules in a laser that results in lasing action. Vibronic transitions are those...

In optical fiber, sharp but microscopic curvatures that create local axial displacements of a few microns and spatial...

A handheld, light-sensitive device that is used with a display console to directly change, measure or erase the visual...

The absorption of a photon raising an electron across the forbidden gap from valence to conduction band of the semiconductor...

A plane mirror mounted on a polar axis that lies parallel to the plane of the mirror. When the mirror is rotated once in 48...

A colorimeter using a spinning disc made of different colored sections for colorimetric analysis.

Measurement of the time elapsed during the current output change from 10 to 90 percent in a photoconductor.

Lidar, short for light detection and ranging, is a remote sensing technology that uses laser light to measure distances and...

A set of rays through a lens originating at a common point and contained in one plane.

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

A still or motion-picture camera designed to photograph through a microscope. Photomicrographic equipment usually contains a...

Computer numerically controlled (CNC) grinding is a manufacturing process that utilizes computerized controls and precision...

A device for converting sunlight into electrical energy, consisting of a sandwich of P-type and N-type semiconducting...

A type of eyepiece, or the modification of an eyepiece, in which a small hole, without a lens, functions as the eye lens;...

The angular difference in the direction of an object as seen from two points of observation. The angle subtended at the...

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

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

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

Photographing of terrain on the ground and objects in the air by cameras mounted in aircraft; utilized in satellites,...

3D Laser Triangulation - A technology that allows sensors to probe the surroundings. Laser triangulation systems have an...

1. An instrument used to determine the visual range in an environment. 2. A type of photometer that artificially reduces an...

A device used in measuring attenuation in optical fiber. The loss caused by the bends in a short reference length of fiber...

An optical element that measures the phase difference between two components of elliptically polarized light to correct for...

The circle that contains the slit, grating and primary astigmatic focus of a concave diffraction grating.

The detection and analysis of naturally formed extraterrestrial electromagnetic radiation within the radio frequency range...

The number of bits used to represent a character.

In a diode laser, a mode in the plane of the active layer that is perpendicular to the direction of the emitted beam.

Attosecond photonics sources refer to devices or systems that generate extremely short pulses of light on the order of...

Functional materials refer to materials that possess specific properties or functionalities that make them suitable for...

Generally, any radiation that can form ions, either directly or indirectly, while traveling through a substance.

A spectrophotometer is a scientific instrument used to measure the intensity of light at various wavelengths in the...

Machinery used to grind and finish a component, such as a lens or prism, to a desired precision. Usually such machines carry...

A prism made up of two air-spaced components. It has the ability to revert, and not invert, an image, and can be used in...

In photography, the technique of taking multiple pictures of the same subject at different exposures to compensate for...

Circular dichroism (CD) is a spectroscopic technique used to study the structural characteristics of chiral (asymmetric)...

A beamsplitting mirror that reflects as a function of wavelength.

A system mounted a few inches above a moving plane that consists of a light source, lenses and one or more phototubes. In...

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

An emission spectrum consisting of bright bands against a dark background.

A lamp, usually incandescent, that has a very compact filament, permitting a greater concentration of emitted light, aided...

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

A photometer that uses a photoemissive tube to detect and measure light. See photoelectric photometry.

A lumen is a unit of measurement used to quantify the amount of luminous flux, which is the perceived power of light. In...

Videography refers to the process of capturing moving images and recording them in a digital format. It involves the use of...

The analysis of the atomic structure of a sample by means of a source radiation that is absorbed and emitted by the sample...

A weight reducing method whereby material from the rear of a reflector is removed leaving a pattern of ribs normal to the...

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

A combination of a polarizer and an analyzer that is used to detect birefringence or rotation of the plane of polarization...

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

A spectrograph that uses a diffraction grating as its dispersive element in place of a prism, and yields greater resolving...

The distance between the object and the cornea, or the first surface of the objective in an optical device.

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

Gamma ray radiation released when matter and antimatter, such as electron and positron, unite and eliminate each other,...

Zone of laser operation in which the direct, reflected or scattered light exceeds the laser's MPE and (by ANSI standards)...

1. A flaw in a blank caused by folding the blank's surface during its formation. 2. The change in the direction of a...

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

A mechanical device designed to smoothly vary the effective diameter of a lens, thereby controlling the amount of light...

The mechanical modification of the shape of the cornea to correct a vision defect.

Photochromic refers to a property exhibited by certain materials, typically organic compounds or dyes, which undergo...

A material that produces stimulated emission during the process of amplification with a laser system.

Cathode radiant sensitivity refers to the ability of a photocathode to convert incident radiant energy, typically in the...

One of the types of change in the energy levels of molecules or atoms in a laser that can result in lasing action. Because...

The capacitance of a capacitor which has a potential difference of one volt between its plates when it is charged by one...

Cyan, magenta and yellow. They are called subtractive because they each subtract one color by absorbtion and reflect the two...

A Babinet compensator that contains the controlled motion of one prism with respect to the other. This idea was introduced...

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

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

In a sequence of laser pulse emissions, the intitial pulse that often helps initiate a reaction at the target surface,...

The maximum number of users who are using a given communication channel. Typically, the number of users at any given time is...

In computer graphics, intersection of a plane with a three-dimensional object to create a sectional view.

A CCD camera, or charge-coupled device camera, is a type of digital camera that utilizes a CCD image sensor to capture and...

A technique used to create a series of interrelated holographic images that give an appearance of motion when projected in...

To control, by magnifying or reducing, the size of a televised image, either electronically or optically.

A process by which a plastic cell is molded around a glass lens or lenses to create a mount, eliminating the metal barrel...

A thin-film device containing miniature optical components connected via optical waveguides on a transparent dielectric...

The ray that has an isotropic speed and maintains a uniform polarization in all propagation directions when traveling in a...

The variation of the electronically detected signal with respect to the scaled version of the classical optical signal...

An instrument for detecting or measuring small electric currents.

The selective absorption of electromagnetic waves by a liquid made up of molecules with permanent dipole movement.

Die bonding is a critical process in semiconductor manufacturing and microelectronics assembly, where a semiconductor die or...

Virtual reality (VR) is a computer-generated simulation of a three-dimensional environment or experience that can be...

Optical phase distortion refers to a phenomenon where the phase of an optical wavefront is altered as it propagates through...

A wireless stereo imaging device used in conjunction with a monitor to produce a virtual interactive environment. Liquid...

A shield of rubber, plastic or metal used to protect the eyes of the observer from stray light and wind, and to maintain the...

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

A GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic...

That branch of astronomy concerned with the study of the moon's physical characteristics.

A dispersion-shifted fiber (DSF) refers to a type of optical fiber designed to minimize the effects of chromatic dispersion,...

The phenomenon whereby certain crystals exhibit spontaneous electric polarization. It is analogous with ferromagnetism.

A multifaceted holographic disc that is rotated by a motor to deflect incident light to a scanning system's lens.

Literally, neodymium:yttrium-aluminum-garnet. A cylindrical rod of yttrium-aluminum-garnet doped with neodymium that is the...

Calculations of lens aberrations whereby the first two terms of the series expansion are the only ones employed....

The process of using a spectrograph with a telescope to acquire information on an astronomical object's speed and physical...

An etalon is an optical device that consists of two parallel reflecting surfaces separated by a precise and known distance....

A discharge tube filled with various gases and used as a source in spectroscopy.

The apparent luminance of the image as seen through an optical system. This brightness of the image is determined by the...

The electric arc that is a particular discharge between two electrodes in a gas or vapor which is characterized by high...

A hologram in which diffraction is produced by the silver image, resulting in a dimmer image than in a phase hologram, where...

All formulas that present the index of refraction as a function of a wavelength of electromagnetic radiation. Also called...

The process by which a vitreous or amorphous substance forms a crystal structure at a specified temperature.

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...

The narrowest line of the cadmium spectrum; the red line has the purest radiation.

Directed energy refers to a type of energy that is emitted and transferred in a controlled direction. The term is often...

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

A photon jet is a narrow, highly collimated beam of light that is formed when light interacts with small dielectric...

A direct method of measuring refractive index that works best with flat-surfaced samples (i.e., those that are not dependent...

A type of radiation detector designed to recognize nonlinear optical effects, such as the Raman effect, by means of a...

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

A nonoptical surface, within lenses and lens mounts, that contributes largely to flare by reflecting light into the image...

1. In fiber optics, a protective material applied as an optical fiber cover that has no optical function. 2. In image...

Expression of the nondimensional coefficient of the heat transfer in a convection process.

An imaging process, similar to specific Doppler mapping radar techniques, that utilizes a laser, an optical imaging system,...

An optical wedge in which transmittance or density is a function of the location of the wedge, relative to a specific...

Light that is directed or focused by means of curved reflective surfaces.

The term "embedded laser" typically refers to a laser device that is integrated or embedded into a larger system or...

A mirror with a coating that reflects infrared radiation and transmits visible light.

A device that measures the wavelength of an electromagnetic wave.

A device containing two opposed quartz wedges of equal angle, one wedge being movable along its length by a micrometer...

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

A field of physics that deals with light as if it truly were composed of rays diverging in various directions from the...

1. The additive process whereby the amplitudes of two or more overlapping waves are systematically attenuated and...

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

Any photographic medium that, when chemically developed, produces an exact photographic reproduction of the original.

An optically pumped solid-state laser in which the active medium is a neodymium ion in a glass rod host. Abbreviated...

The nonthermal conversion of electrical energy into light in a liquid or solid substance. The photon emission resulting from...

The ratio of the illuminance at the peak of the diffraction pattern of an aberrated point image to that at the peak of an...

A color-television viewing system with three kinescopes, three lenses and three deflection yokes used to form the red, green...

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

The optically pumped, solid-state laser that uses sapphire as the host lattice and chromium as the active ion. The emission...

The angular subtense of the field of view in the image space of a telescope, as differentiated from that in the object space...

An imperfection in optical glass consisting of a distinct streak of transparent material having a slightly different...

An optogenetic technique that embeds genetically-engineered proteins to the heart to aid in terminating arrhythmias. After...

1. A geometrical arrangement of two or more light beams for use in laser shows, object detection or other applications...

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

Holmium lasers are a type of medical laser that utilizes holmium-doped crystals as the gain medium. The term holmium laser...

An optical device capable of transforming unpolarized or natural light into polarized light, usually by selective...

A device using the Kerr effect to read back the signals from mechanically recorded tapes and discs. It consists of a light...

An electron instrument used to reflect an electron beam totally.

A jet of inert gas along a laser welding beam's axis that cools, protects or cleans the work surface.

Pyramid error in optics refers to an aberration in the shape of an optical surface, particularly in the context of mirrors....

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

In optics, the term denoting the lack of a fixed phase relationship between two waves. If two incoherent waves are...

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

Structural surfaces that incorporate an embedded sensor network capable of detecting flaws within the structure.

A computer circuit that supplies the action of problem-solving functions or operations.

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

Any of the many devices used to detect the presence of radiation from a specific region of the electromagnetic spectrum.

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

Ratio of the radiance of the specimen to that of a perfect reflecting or transmitting diffuser identically irradiated.

Double-clad fiber (DCF) is a specialized optical fiber that features two concentric cladding layers surrounding a core. The...

A process of color photography in which colors are added one to another in the form of light, rather than as colorants, to...

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

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

A technique for obtaining improved resolution of images produced by large telescopes and distorted by the effects of...

The light flash, produced in flash photolysis, that is triggered within a second discharge tube by the third electrode. It...

An optical system with object and image points at infinity. Literally, "without a focal length."

Camera Link HS (high speed) is a standard developed for high-speed digital data transmission in machine vision and...

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

The phenomenon that can render an optical resonator the equivalent of a semiconductor flip-flop. A bistable device will...

The calculated normal distance from a photon source at which harmful interaction with the incident light will occur....

Chemical vapor deposition is a process of applying dopants to a glass bait by flame reactions of gaseous compounds. See also...

A large-scale, precise drawing of the contours of a perfect mechanical part, often with plus and minus tolerances drawn or...

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

Concerned with the transmission and reception of both sight and sound. An audiovisual system communicates pictorial images...

An interferometric technique for the generation of precision gratings that allows for sequential exposure of small segments...

A scientific CMOS (complementary metal-oxide-semiconductor) camera is a type of digital camera specifically designed for...

In data communications, the simultaneous operation of a circuit in both directions is known as full duplex; if only one...

A defect in the cleaved end face of an optical fiber, defined as multiple surface irregularities across the fiber surface. A...

An astronomical telescope is a type of optical instrument designed to gather and magnify light from distant celestial...

With respect to television, that part of a color television circuit that combines the I, Q and Y signals, and changes them...

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

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

Also known as radiation thermometer. A pyrometer in which the radiant intensity from the source to be measured is used to...

An electromagnetic device used to separate isotopes of elements based on their respective masses.

With respect to photography, the law stating that the optical density of an exposed emulsion with standard development is a...

That image remaining on the detector after the primary stimulus has been removed. In the visual system, the after-image...

A cathode-ray tube that increases the brightness or size of an image or forms a visible image from invisible radiation. The...

A telescope that uses a reflecting objective to focus an image of a distant object at a focal point.

The alteration of electric conductivity produced by the absorption of varying amounts of radiation composed of photons.

The picture area scanned per second.

Straight line travel. This denotes the fact that light travels in a straight line when traveling through a medium with a...

In computer graphics, a character generator that produces alphabetical and numerical characters with some punctuation and...

A night-vision device that uses one or more infrared transducers to scan a scene in the 3- to 5-µm or 8- to...

An eyepiece located at the near end of the microscope tube. It often is a simple Huygens eyepiece, but compensating and...

An electromagnetic wave lying within the region of the frequency spectrum that is between about 1000 MHz (1 GHz) and 100,000...

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

Coating carried out in a sealed chamber evacuated by a mechanical pump in series with an oil diffusion pump to a pressure...

An embossed or marked disk, constructed out of a transparent material and used with a camera system to soften an image.

The study of the reversible conversion of chemical energy into electrical energy. Electroplating is an electrochemical...

A connection, typically made up of one or more cables, between a laser head and a separate power supply. Flexible pipes or...

Custom lapping and polishing services involve specialized processes used to improve the surface finish and dimensional...

An instrument that photographs the spectra of an extraterrestrial object.

A laser having a lasing material that is a fluorescing organic dye. Depending on the dye used, it can produce emission in...

A material, often a liquid or cement, whose refractive index is nearly equal to the fiber's core index, used to reduce...

Computer output in the form of pictorial representation (graphs, charts, drawings, etc.) that is displayed visually.

A compound prism consisting of an assembly of small prisms cemented together that is used in a coincidence rangefinder to...

Two-photon excited fluorescence (TPEF) is a nonlinear optical method that allows imaging of biological cells and living...

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

Optical coherence tomography (OCT) is a non-invasive imaging technique used in medical and scientific fields to capture...

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

Distance between the front vertex of a lens and the object.

A measurement of the spatial resolution of a line or area array in an optical character recognition scanning device.

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

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

Metamaterials are artificial materials engineered to have properties not found in naturally occurring substances. These...

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

A detector and signal demodulator used in optical communications systems to receive a signal and often to translate it into...

The final correction of a polished surface or of an angle to the specified precision.

The basis of color vision in the human eye. Three types of cones have been identified, each having a unique spectral...

An acid used to etch the surfaces of particular materials. For glass, hydrofluoric acid is used either as a liquid or a...

With respect to a crystal, having three unequal axes intersecting at angles, only two of which can be equal and only one of...

A spectrophotometer that measures the amount of ozone in the atmosphere through a comparison of solar energy at two...

Immunohistochemistry (IHC) is a method for detecting antigens or haptens in cells of a tissue section by using labeled...

Situation in which the observer requires fewer than three independent stimuli to make color matches. Dichromats require only...

An opaque shielding device designed to reduce the effect of stray light on an optical system.

A spectrograph used to detect radiation in the range of the ultraviolet in the electromagnetic spectrum. It is made up of...

A common aberration in lenses covering large fields of view; it results in images of objects near the edge of the field...

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

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

Source of radiation defined or specified by its spectral power distribution.

The optical form of the crystal fluorspar, calcium fluoride, that is utilized for its low optical dispersion, its low...

Two-photon polymerization (TPP) is a technique used in additive manufacturing, specifically in the field of 3D printing. It...

Photobleaching is a phenomenon in which the fluorescence of a fluorophore (a fluorescent molecule or dye) is permanently...

Alphanumerical description of color according to Munsell hue, value and chroma.

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

A pixel, short for "picture element," is the smallest controllable element of a digital image or display. It is a...

The conversion of a still picture into sound waves and its subsequent transmission by radio.

The luminescence of a substance that is produced by energy within it (e.g., radioactive material).

An experimental research technique by which absorbed or unabsorbed radiation is analyzed in order to characterize and...

Used in halftone screens to change the fundamental sampled spatial frequency of the halftoned picture, as well as varying...

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

A method for measuring the index profile of an optical fiber by measuring the reflectance as a function of position on the...

In semiconductor physics and materials science, the term "III-V materials" refers to compounds composed of elements from...

A grating with ridges of rectangular cross section, generally equal in width to the space between. This type of grating may...

A theoretical, ideal lens capable of producing perfect images. Used as a lens design and analysis tool to image collimated...

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

A material property that is the inverse of its resistance to the flow of electricity.

A vacuum tube with an electron gun at one end and a fluorescent screen at the other. Electrons emitted from a heated...

The holographic recording of sequences of high-speed phenomena. With a multiple beam laser, multiple holograms that depict...

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...

That part of the science involved in the study of the theory and interpretation of spectra that uses the unique...

In an optical waveguide,- typically a multimode fiber - the distortion resulting from differential mode delay, i.e. axial...

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

A two-mirror lens design used in astronomical telescopes, the primary being a parabola, the secondary a smaller hyperbola....

A device used in ultrasonic imaging to measure the velocity and attenuation of compressional waves in a transparent liquid...

An assembly of multiple prisms that disperses incident light into its spectral components without deviating light at the...

That point in the electromagnetic spectrum at which an optical system focuses the most chemically effective rays.

A line of the Raman spectrum that fulfills Stokes' law because it possesses a wavelength that is greater than the radiation...

A crystalline ferroelectric material used primarily as a substrate and an active medium for thin-film optical modulators and...

Any pyrheliometer that has a filter placed over its sensor to limit the range of solar radiation it will detect; used to...

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

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

Gram-negative bacteria are a group of bacteria that possess a cell envelope composed of a thin layer of peptidoglycan...

A slab-shaped, very low profile package for electronic components; often used when printed circuit boards must be closely...

1. The photosensitive membrane on the inside of the human eye. 2. A scanning mechanism in optical character generation.

An optical combiner, in the context of optics and display technologies, refers to a device or component that combines...

The optical element that receives light from the object and forms the first or primary image in telescopes and microscopes....

A gelatinous fluid that can be used as a porous thin-film coating for optical components, including laser beam collimators,...

Fusion ignition refers to the point in a controlled nuclear fusion reaction where the energy released by the fusion...

Nonimage-forming light, concentrated or diffuse, that is transmitted through the lens to the image. It is frequently the...

An impurity-doped silicon detector array sensitive to long infrared wavelengths, installed in optical collecting systems...

Luminescence is the emission of light that occurs without the involved substance undergoing a significant increase in...

The criterion maintaining that if light follows a specific path through an optical system, it will, if reversed, traverse...

Nondestructive measurement of the delta and alpha of clad optical fibers that involves interferometry with the fiber...

The field of view (FOV) refers to the extent of the observable world or the visible area that can be seen at any given...

A type of color-generating cathode-ray tube that uses a shadow mask, a thin perforated electrode, located close to the...

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

In the context of optical materials, the term "impurity level" refers to the presence of foreign atoms or molecules within...

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

On a display monitor, a small, mobile rectangle, cross-hair or pointer that locates a feature in an image that is the object...

Mathematically defined as the product of etendue (or throughput) and the square of the refractive index, the optical extent...

Spectral repeatability refers to the consistency and reproducibility of spectral measurements across multiple trials or...

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

A phenomenon, exploited for medical imaging, in which the nuclei of material placed in a strong magnetic field will absorb...

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

Reflectance spectroscopy is a technique used to analyze the reflective properties of materials across various wavelengths of...

A type of semiconductor diode used in voltage-limiting circuits; when voltage reaches a certain value, the device becomes a...

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

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

Controlled beam technology that introduces beams of sunlight through holes in a roof that are relayed throughout the...

1. Generally, an emulsion mask having a clean annular region in an otherwise opaque region. It is designed to eliminate...

The application of coherent wavefront techniques to the determination of the physical state of a system without appreciably...

Successive layering of resistive, dielectric and conductive inks on a substrate by a type of screening process.

A condenser composed of a paraboloidal reflector and used for dark-field illumination.

The displacement of spectrum lines, as determined by the increasing distance between, and the relative velocity of, the...

Collisional absorption of energy that occurs in inertial confinement fusion systems when hydrodynamic expansion of the...

Stochastic optical reconstruction microscopy (STORM) is a superresolution microscopy technique that enables imaging of...

A primitive crystal possessing two plane surfaces that form a dihedral angle bisected by another plane surface.

Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In...

An optical system that superimposes a synthetic display providing navigational or weapon-aiming information on a pilot's or...

The study of the celestial bodies, relative to x-ray emission. Satellites launched to study x-ray sources have revealed many...

Also known as analog thermogram. The resultant photograph, illustrating, in tones ranging from black to white, the spatial...

A type of interferometer in which two coils of optical fiber are arranged so that light from a single source travels...

The freeing of electrons from a filament in an electron tube as the result of the filament being heated by an electric...

A PN-PN device with incident light taking the place of gate current; three of the four semiconductor regions are available...

A process used to detect minute gravitational fields and to display images from objects by means of radiated gravitational...

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

A paraxial light ray that extends from an object point on the optical axis.

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

A device used in the sputtering of thin films, in which a magnet system on the back of the cathode deflects the electrons,...

A television system designed to obtain pictures of objects or scenes beneath the surface of the water. Generally, a...

Sometimes referred to as the surface normal or 'surface norm'; the normal is an axis that forms right angles with a surface...

The law stating that the angle of reflection is equal to the angle of incidence, the incident ray, reflected ray and normal...

The large, usually flat surface onto which an image is projected for viewing. May be reflecting or transmitting (rear...

An atom that has gained or lost one or more electrons and, as a result, carries a negative or positive charge.

The potential difference between two areas of a semiconductor when one is exposed to light.

Refers to the characteristic hue of the ocean according to the presence and concentration of specific minerals or...

The physical area containing an assembly of computer graphics equipment for presenting generated images and allowing...

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

A graph of the intersections of a fan of rays with the final image plane, plotted as a function of the positions of the rays...

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

A function used in a convolution filtering operation. The image to be filtered is convolved with the filtering kernel to...

An optical fiber's absorption of electromagnetic waves due to hydroxyl ions remaining after contact with water.

A thin layer of metal deposited on the surface of a substrate. The film may serve as a reflector, beamsplitter, neutral...

Pertaining to electromagnetic radiation as perceived by the eye; that is, with the contributions as wavelengths in the...

An optical assembly refers to a collection of optical components that are carefully arranged and aligned to perform a...

The energy passed on as electromagnetic radiation; e.g., radio, heat or light waves.

The spectrum formed by a dispersing prism or a dispersing prism system.

A charge-coupled device (CCD) is a type of electronic image sensor used in various imaging devices, including digital...

Whole slide imaging (WSI), also known as virtual slide microscopy or digital pathology, is a technology that involves the...

The point of intersection of the optical axis with any centered optical surface.

A surface imperfection caused by a polisher running dry too long. It occurs with felt or plastic polishers, and may appear...

A waveguide is a physical structure or device that is designed to confine and guide electromagnetic waves, such as radio...

A thermal radiation detector consisting of a small cell with a blackened plastic front face that bulges slightly when heat...

The use of an applied electrical field to focus a cathode-ray tube's electron beam.

A coil used to focus an electron beam by the generation of a magnetic field parallel to the beam.

A technique whereby the sample is illuminated by a hollow cone of light larger than the acceptance angle of the objective,...

An infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating...

A feature of some imaging devices, such as digital cameras, that allows them to compensate for different lighting conditions...

A representation of the shape of a surface, including any roughness or other irregularities. The profile can be generated by...

The ongoing expansion of the universe based on observations of the recession of distant galaxies from each other as...

An optical scanning device designed to read information printed in the form of bars of different size by detection and...

A reproduction made of an original grating -- usually by casting thermosetting plastics onto the original -- to avoid the...

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

The ability of the two eyes to see an object from two slightly different points of view. This difference allows an...

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

A dye laser cell configuration in which the dye flows in the direction of the axis of the laser, yielding symmetrical energy...

In a camera, the movement of one or more lenses behind the front lens, rather than of the front lens itself, to bring the...

Ratio of radiant flux weighted according to V(l), the spectral luminous efficiency, to the corresponding radiant flux.

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

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

The technique of producing spectrograms in wavelengths beyond 120 nm by the use of a diffraction grating and a Schumann...

The actual width of a bevel rather than its width projected along the lens aperture.

A relay that opens or closes an electrical circuit depending on the intensity of the light incident to a photoelectric...

An afocal optical device made up of lenses or mirrors, usually with a magnification greater than unity, that renders distant...

A small bulb containing a conducting gas, an arc being formed between a metal ring and a tiny zirconium electrode near the...

The principal point of a lens relative to the object space.

Chirped pulse amplification (CPA) is a technique used in laser physics to amplify ultrashort laser pulses to high energies...

An instrument designed to measure the numerical aperture of an objective.

A chemical substance that exhibits fluorescence when excited by ultraviolet radiation, x-rays or an electron beam. The...

The physical adaption of the eye lens, by means of ciliary muscle contraction, in order to maintain a clear, in focus image...

In dry etching, a method of characterizing the composition of solid materials such as metal. Atoms in the OES technique are...

Solar regions characterized by low density and open magnetic fields where high-speed solar wind streams originate....

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

An ion carrying a positive charge and thus attracted to the cathode during electrolysis.

An optical table, also known as an optical bench or an optical breadboard, is a specialized platform used in optics...

Method for reducing laser speckle in which the object field comes from a real diffuse object or the reconstructed object...

An LED, or light emitting diode, is a semiconductor device that emits light when an electric current passes through it. LEDs...

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

A telescopic light-sensing meter used to measure illumination levels of small regions at a distance of many feet; it is used...

The coupled pairs of electrons that carry supercurrents through the body of a superconductor, relative to a coherent...

Luminous flux incident per unit area of a surface; luminous incidence. (The use of the term "illumination" for...

A method of thin-film deposition in which electrons boiled off a heated cathode are used to melt the coating material. If a...

As a wavefront of light passes by an opaque edge or through an opening, secondary weaker wavefronts are generated,...

The optical diffraction spectra formed, or the method that produces them, when a light beam is transmitted through a...

A system used to measure very small displacement by electrical means.

In gradient index optics, a gradient profile in which the refractive index varies symmetrically about a point.

The signal-to-noise ratio (SNR) obtained with a Fourier transform spectrometer when detector noise prevails, which exceeds...

Microscopy technique to convert the phase structure of the wave transmitted or reflected by the specimen into a...

An aberration that remains after primary color is corrected. Primary color causes the back focus of a lens to vary with...

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

The negative distortion that causes a square grid pattern to be imaged as barrel-shaped.

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

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

Laser surgery refers to a medical procedure in which a laser, or focused beam of light, is used as a precision tool to cut,...

The recording achieved when a surface, illuminated by a signal-controlled light beam, emits electrons or reacts in some...

Linear optics refers to the study and manipulation of light in a linear and deterministic manner, where the response of...

With respect to color photography, the measurement, at a given wavelength, of the way the color film modulates the radiant...

Also known as RAMP microscopy, random access multiphoton microscopy is a microscopic technique that uses multiple...

A lamp that emits light when an electric current passes through a resistant metallic wire situated in a vacuum tube.

A technique in photometry that uses an oxyhydrogen or oxyacetylene flame to optically excite a solution containing the...

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

A communications system that can transmit in only a single direction at a time. See duplex.

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

An instrument that uses electromagnetic fields to sort out the relative masses of atoms and molecules.The same way an...

Plasmon ion-assisted deposition (PIAD) is a technique used in thin-film deposition processes, particularly in the production...

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

An EMCCD (electron-multiplying charge-coupled device) camera is a type of scientific camera specifically designed for...

That radiation characterized by wavelengths ranging from 0.2 to 0.3 µm in the electromagnetic spectrum.

The control of free electron movement through the use of electrical or magnetic fields, and use of this electron movement in...

The photographic recording of the heat radiation emitted from various points on the object as corresponding density...

A simple electrostatic lens with a focus controlled by a single potential difference.

A microchannel plate (MCP) is a specialized electron multiplier device used in various applications such as particle...

That portion of physics concerned with motion in the abstract, such as of points or space figures, and separated from its...

A pump-probe technique whereby a single wavelength source may be used in order to excite a given sample to determine...

The ratio of the first focal length of a lens to the refractive index of the medium containing the incident light; the ratio...

A traveling wave tube (TWT) containing a photocathode and window that, receiving a laser beam, produces a modified...

A spectrograph in which the refracted beam returns almost along the path traveled by the incident beam, and is brought to a...

Equipment used for chemical analysis by investigation of the spectra formed and observed in chemical activity. Of particular...

A bundle of rays that originates from an object point on the optical axis of a lens system.

Free-space optics (FSO), also known as optical wireless communication or optical wireless networking, refers to the...

Dispersion that occurs when the medium's index of refraction decreases as the frequency of the propagating light increases....

A structural method of optical character recognition, used where the input media are variable, as in hand-written or...

That property of a substance that determines that there will be a decrease in conductivity when exposed to light radiation.

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

A reflecting or refracting surface contained within an optical system.

An extremely short, high intensity electronic flash of light, having a duration of about 1 x 10-6 s, used in photographing...

Relative power distribution as a function of position or angle.

Measurement of surface roughness or quality through the use of a diamond-pointed stylus connected to a coil in an electric...

That part of the infrared spectrum from about 30 to 1000 µm.

Also referred to as a band-stop or band rejection filter; a notch filter is a filter that is designed to screen out a very...

A medical imaging method in which gamma camera heads rotate about the patient to detect radionuclides, enabling physicians...

A defect in the cleaved end face of an optical fiber, in the form of a sharp protrusion at the edge of the fiber.

Light consisting of a single wavelength or a very narrow band of wavelengths.

A camera system in which the image formed on the fluorescent screen of an image converter tube in the system is recorded by...

Pertaining to electromagnetic radiation, with the contributions at all wavelengths of interest weighted equally.

The emission spectrum formed by the radiation from a sample that has been evaporated by a nonluminous flame.

Flow chemistry, also known as continuous-flow chemistry, is a chemical manufacturing process where reactions take place in a...

A phase-shift interferometer used to detect the relative angular speeds or positions of two concentric rotors.

A cosmetic defect on the surface of an optical element. A dig is nearly equal in terms of its length and width. The size is...

A high-speed, narrow-field lens consisting of two achromats spaced about the aperture stop. Its uses include portrait...

A camera equipped with a lens and a long length of perforated film, the latter being moved intermittently between exposures...

A calorimetric calculation from which the temperature vs. time dependence of any point on a sample can be determined,...

The photographic recordformed in macrophotography in which the size of the small nearby object at theimage plane is the same...

The decay of an electrostatic charge image resulting from long exposure to the dark.

The interaction of charged particles and electromagnetic fields.

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

A camera capable of making successive exposures on a continuous film driven by accurately spaced sprocket holes (a motion...

Dichroism refers to the property of certain materials to exhibit different colors or absorbance of light depending on the...

Technique that defocuses activity from surrounding planes by means of the relative motions at the point of interest.

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

A device used to detect and measure the quantity of exposure to nuclear or x-ray radiation, and dependent on the fact that...

The total luminous flux given out per unit area; i.e., the sum of the luminous emittance and any radiation that is reflected...

In a dual-ring local area network, a node that is connected only to the primary, active ring and not to the secondary ring...

Seidel aberrations refer to a set of monochromatic aberrations in optical systems, named after the German mathematician and...

An electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an...

A liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the...

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

The radiation produced when a charged particle traverses a medium that has a refractive index considerably greater than...

An optical projection device designed to project positive color transparencies onto a screen for viewing.

A double meniscus system in which two achromatized meniscus lenses are arranged symmetrically on either side of the aperture...

The law expressing the condition under which a crystal will reflect a beam of x-rays with the greatest amount of distinction...

In the spectral sense, an optical source that emits one or more spectrally narrow lines as opposed to a continuous spectrum....

Nanopositioning refers to the precise and controlled movement or manipulation of objects or components at the nanometer...

Rockwell hardness (Rc) refers to a method for measuring the hardness of a material, primarily metals, using an indentation...

1. With respect to radiation, a device used to attenuate particular wavelengths or frequencies while passing others with...

A small mass spectrometer used to find leaks in a vacuum system by detecting the presence of helium. Using a magnetic...

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

A device that permits only electrons within a narrow velocity range to pass through it, while rejecting those above and...

The thick edge of a refracting prism.

A whole-flow-field technique providing instantaneous velocity vector measurements in a cross-section of a flow that is...

See charge-coupled device; charge-injection device.

1. A device generally used in a cathode-ray or camera tube to emit a stream of electrons moving at uniform velocity in a...

In physics, the law of reversibility is often associated with the concept of reversibility in thermodynamics. The law...

Light diffusion refers to the process by which light is scattered or spread out in various directions as it interacts with a...

A protective jacket added to an optical fiber to facilitate use in harsh environments. Armor usually consists of steel or...

1. The variation in intensity of a light beam as it travels through the atmosphere. 2. In radiation physics, a light flash...

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

The coefficient termed by Callier as the ratio between the density of photographic negatives measured by parallel light and...

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

High power laser ablation device that by pulsed operation produces holes of controllable dimension on the scale of microns....

A contour mapping technique that uses electronic scanning and sampling techniques instead of a reference grating (see moire...

An optical system that records inhomogeneities within a medium by detecting the energy refracted by that portion of the...

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

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

A heterochromatic photometric process using successive comparison of similar chromaticities and the calculation of relative...

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

In a communications network, a point at which data are received or from which they are sent. Though the term often is used...

Diamond turning refers to a precision machining process used to produce complex optical components, particularly lenses and...

A light source that does not fluctuate despite temperature changes.

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

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

The constant outward flow of weakly magnetized plasma from the sun that is deflected by the magnetic field of the earth and,...

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

The measurement of the intensity of spectral lines by the examination of a very small area under a microscope and the...

An immersion liquid used to treat polarizing filters to eliminate the effects of surface variations and to minimize the...

An electrically excited laser having carbon monoxide as the lasing material and in which lasing occurs in a partial...

The product of the actual base or baseline of a rangefinder or heightfinder, and the power or magnification of the...

The use of optical or electronic recording systems to extract information from the terrain, while aloft, for reconnaissance...

Piezoresistance is a phenomenon in materials science and physics where the electrical resistance of a material changes in...

A doubly refracting crystal having a single axis along which there is an absence of double refraction.

Temporal jitter at a signal's receiver when amplified noise causes frequency shifts, as with a soliton traveling through an...

An atomic clock is a highly precise timekeeping device that uses the vibrations or oscillations of atoms as a reference for...

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

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

Radiation that does not produce free electrons and ions, or electrically charged particles.

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

Electron lens consisting of an homogeneous axial electric field.

Light-absorbing material that is applied to the back support of any bright image under inspection to prevent the formation...

A powerful method, referred to as FCS, for determining the average diffusion coefficients of fluorescent molecules in...

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

A technique used in radiography to determine a crystal's structure by obtaining radiographs of it in powder form, normally...

Flux per unit solid angle and per unit area measured normal to the direction of propagation of the flux.

Metasurfaces are two-dimensional arrays of subwavelength-scale artificial structures, often referred to as meta-atoms or...

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

Pertaining to or as a function of wavelength. Spectral quantities are evaluated at a single wavelength.

Basically, a hydrogen atom with two alterations, positronium is the lightest atom in the universe and has an extremely light...

That object distance at which a camera must be focused so that the far depth of field just extends to infinity. The near...

A cathode-ray tube in which secondary emission electrons form a display of high intensity.

The field of photography concerned with the recording of subjects beneath the water with a watertight, water-resistant...

Transmission loss in optical fibers caused by packaging processes; it is considered a power-coupling effect from the guided...

A photodetector composed of a semiconductor material whose responsive properties can be altered by the addition of...

The tendency of charge carriers to spiral about an axis in a direction identical to that of an applied magnetic field that...

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

The separate spectral lines formed by a diffraction grating that are characterized by one wavelength difference in path...

Epitaxial refers to the growth of a crystalline layer on a crystalline substrate in such a way that the orientation of the...

A measure of the wavelength extent of a spectrum.

A fiber-coupled photoconductive antenna (FCPA) is a type of optoelectronic device that combines a photoconductive antenna...

Also called proximity focus image intensifier. A compact image intensifier that utilizes a microchannel plate...

In spectacle lenses, the lateral measurement of a multifocal segment at its maximum width.

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

A device that measures the intensity of photochemically active radiation, particularly from the sun. One form of this...

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

An InGaAs (indium gallium arsenide) camera is a type of imaging device that utilizes InGaAs sensors to capture images in the...

A lens made up of a dielectric material that is capable of influencing radio waves much in the same way an optical lens...

The term "Rydberg atom" refers to an atom in a highly excited state where one or more of its electrons are in a Rydberg...

A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized...

An instrument consisting essentially of a tube 160 mm long, with an objective lens at the distant end and an eyepiece at the...

A cylindrical convex viewing mirror used for viewing distorted pictures formed by photographing the reflections of the...

A molecular motor refers to a nano-sized device composed of organic molecules or other small-scale components that can...

The effect that the optical losses in a medium can grow when the medium is irradiated with light at certain wavelengths.

The maximum distance at which the stereoscopic effect may be observed. With respect to the unaided human eye, it has been...

A lens designed for projection of color transparencies.

An image intensifier tube that uses a magnetic field for focusing. It yields high-quality images, but its use is limited by...

A light therapy that utilizes nonionizing light sources, including lasers, LEDs, and broadband light, in the visible and...

The law given by the formula: that is, the frequency of radiation emitted or absorbed by a system when E2 and E1...

A machine vision technique that compares a template of the desired image (the correlation kernel) with the actual camera...

In the region of a Gaussian beam focus by a diffraction-limited lens, it is the axial distance from the point of minimum...

The light ray leaving a reflecting surface, indicating the path of light after reflection.

A method of focusing an optical system by moving the front component (the lens closest to the subject) to change the...

A thermionic tube that has a velocity-modulated electron stream and that may be used as a microwave amplifier or oscillator.

Dispersion characterized by an increasing index of refraction in the medium as the frequency of the propagating light...

The distribution of electromagnetic fields in a given area. The units are volts per meter, watts per meter squared and...

Having the characteristics of glass.

An optical system having one or more lens or mirror components that have nonspherical surfaces. These surfaces, whether...

A small xenon-filled tube with metal electrodes fused into the ends. The gas flashes brilliantly when a condenser is...

Fluorescence imaging technique in which the excitation light from the objective is directed into the sample producing...

1. The basic unit of length in the metric system, equal to 39.37 in. or 3.28 ft. 2. Any device or instrument used for...

A maser that relies on the fact that electrons in orbital motion in high-magnetic fields will emit energy at the cyclotron...

An image intensifier that uses electrostatics to amplify and focus the electronic image.

A type of mosaic detector array that combines features of scanning and staring sensors by using a small rapid scanning...

In optics, the term image jump refers to a displacement or shift in the apparent position of an image when a change occurs...

A superposition of many zone plates, each reconstructing a real and virtual point image at the appropriate locations upon...

CID, or charge injection device, camera refers to a type of imaging device that utilizes a specific kind of solid-state...

Computer hardware or firmware that accesses character patterns stored in read-only memory and displays them at specific...

Type of solid-state display tube in which the readout surface is coated with a material that changes color when positively...

Photodynamic inactivation (PDI) is a therapeutic approach that utilizes the combination of light, a photosensitizer, and...

The mathematical evaluation of an optical system to determine and quantify its basic optical properties and image quality...

A device consisting of a disc with a spiral arrangement of holes that is used to convert visible patterns into electrical...

In an interferogram, an intense portion of the recording that corresponds in size to the amount of infrared radiation...

The analysis of fluorescence emitted by discrete atoms, in flames, that have absorbed radiation from an external source. It...

An instrument used to test lenses by utilizing the optical transfer function. It consists of a HeNe laser, a beamsplitter...

The unit of the dose of any radiation that produces the same biological effect as one roentgen of x-ray.

A thermocouple that is used in infrared spectroscopy to detect a sample's infrared emittance. See thermocouple.

A container which secures multiple splice trays and protects the trays and their contents from damage.

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

The photographic record of the diffraction pattern formed when x-rays pass through a crystal.

(TOF) The length of time needed for a signal to arrive at and be reflected from the target. The basis of an active...

Luminous flux emitted from a surface per unit solid angle per unit of area, projected onto a plane normal to the direction...

In a microscope, the optical assembly that focuses light on the specimen and into the objective.

A mirror blank refers to the initial piece of material from which a mirror is made. It is typically a flat or slightly...

A zone plate in which the zones are alternately transparent and opaque to specific radiation, and coarse enough so that no...

A crystal diode whose rectifying activity is determined by the touching of the crystal to a finely pointed wire surrounded...

The relationship between different wavelengths of light generated by a source, which may affect the spectral distribution of...

1. A bundle of light rays that may be parallel, converging or diverging. 2. A concentrated, unidirectional stream of...

The term for an image captured by a detector and from which a dark frame, bias frame and/or flat-field frame can be...

A framework or latticework having an even arrangement of rods, or any other long narrow objects with interstices between...

Process that occurs when a polymerized soft plastic rod with higher refractive index is placed in a bath of a lower...

A frame taken with a CCD camera of a surface that is evenly illuminated by diffuse light. This frame shows irregularities in...

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

A thermometric instrument used for the detection and measurement of radiant energy. Its essential component is a short...

The maintenance of a fixed-phase relationship across the full diameter of a cross section of a laser beam.

Laser lithotripsy is a medical procedure that uses laser energy to break down or fragment stones in various parts of the...

An array of lines in the infrared region of the emission spectrum of atomic hydrogen. Their wave numbers are expressed by...

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

An aspheric mirror is an optical mirror surface that deviates from the shape of a perfect sphere, having a non-spherical...

The movement of an object seen through a refracting prism toward the apex of a prism.

A device used to delay transmission of a signal for functions such as memory loops, sequential processing or built-in...

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

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

The resulting contraction or expansion of a piezoelectric crystal along an electric axis when the crystal is under the...

Energy loss encountered at connectors in optical fiber transmission systems. The major contributors are mutual core...

A beam of light whose electrical field amplitude distribution is Gaussian. When such a beam is circular in cross section,...

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

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

A mechanism or device, especially a coating with a refractive index equal to or slightly greater than that of an optical...

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

A family of specialized instruments used by ophthalmologists and optometrists to study a patient's eyes and prescribe...

A robotic process commonly employed by automakers that enables high-speed and flexible production throughput by using...

A measure of the sensitivity of a detector; the reciprocal of noise equivalent power (NEP). See D*.

A device that enlarges and strengthens a signal's output without significantly distorting its original waveshape. There are...

The transfer of energy from an incident electromagnetic energy field with wavelength or frequency to an atomic or molecular...

A technique for detecting free radicals by their electronic spectra. The material to be studied is placed in a...

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

In a microscope, the diaphragm located between the Bertrand lens and the eyepiece, which is closed during conoscopic viewing...

The unchanging nature of spectral reflectance as vegetational density increases to the point where additional increases in...

Hardware installed on fiber cable ends to provide cable attachment to a transmitter, receiver or other cable. Usually a...

A process involving the interaction (absorption, emission or both) of two or more photons with a molecular entity.

The projection of a plane or grid pattern of light onto an object. It can be used for the determination of three-dimensional...

A device composed of dissimilar metals that, when welded together, develop a small voltage dependent upon the relative...

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

Graphene is a two-dimensional allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal...

1. A term used to describe the clouded appearance of an incompletely polished surface that scatters light. 2. The...

A solid-state semiconducting structure (basically one of the bolometers) that changes electrical resistance with...

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

A vision defect commonly referred to as nearsightedness. The defective condition results when the image of a distant object...

A filter used in photography to change the spectral composition of light entering a camera, or to adjust color balance...

1. A prism used in some instruments to bend light 90° before it enters the objective. 2. A dispersing prism located in...

A cell filled with a transparent material that, when placed in a strong electrical field, exhibits double refraction. Since...

Characteristic of an absorber in the IR region, whereby absorption increases as a direct function of the intensity of the...

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

An instrument designed to measure radiation indirectly through the use of several phosphors and a photomultiplier tube. The...

A dielectric sphere with an index of refraction that varies with distance from the sphere center. A parallel beam of rays is...

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

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

A term referring to various processes for forming visible images outside of a camera to be photographed on ordinary film....

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

Integration time, in the context of optics, imaging systems, and sensor technology, refers to the duration over which a...

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

A quadrivalent semiconductor material, with electrons as the majority charge carriers, that is formed by doping with donor...

A toric lens generated by rotating a specific cross section about an axis beyond its area and used in the formation of...

In target tracking, a technique for speeding up the image processing by removing bunches of pixels that are outside the area...

A spectroscopic process that detects and analyzes the discharge from an extrinsic surface with less than bandgap light. This...

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

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

In rangefinders and height finders, a rotatable or sliding wedge-shaped element used to divert the line of sight precisely...

A double block formed by placing two adjoining, equally thick sections of quartz, one being dextrorotary, the other...

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

A fiber optic imaging bundle is a specialized optical device composed of multiple optical fibers bundled together. Each...

A method of erasable optical data storage in which information is stored by visible light, then read by illumination with an...

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

The roughness profile shape from which light scattering is expected to occur.

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

MicroRNAs (miRNAs) are a class of small, single-stranded RNA molecules, typically consisting of about 19 to 24 nucleotides,...

Expression of the length of a transmission medium in terms of wavelengths of the propagating wavelength. In general,...

The smallest amount of photon energy to pass a detector window and be counted.

A satellite-borne remote sensing device capable of transmitting images at 10 and 20 m resolution from an altitude of 830 km,...

The interval between direction of signal to a light-emitting diode and attainment of 10 percent output current in the...

Observed phenomenon in laser pulses in which a large number of excited electrons are created and in which multiphoton...

Technique in which the polarization rotation of light, and its relationship to the magnetic field strength can be analyzed...

Typically used for the examination of manufactured or engineered parts, an optical gauging device, in which a backlight is...

The spot illuminated on a cathode-ray tube by the initial impact of the scanning ray and the screen.

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

Plasma-enriched deposition or planar magnetic sputtering that offers increased deposition rates in optical thin-film...

A reflecting surface that scatters radiation that is incident on it, thus producing diffuse reflection.

Data communications network in a clearly defined geographical location, and extending no more than a few miles in length. It...

A convex or positive lens that serves to collect energy and direct it into subsequent system optics.

Often referred to as the geometric center of a given image or image plane, the centroid of an image is a fixed point located...

A visual, single-unit spectrophotometer with a biprism and a Wollaston prism. The Wollaston prism polarizes coincident...

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

An input device for a computer that detects and reads the data, in the form of punched holes in cards, by light that is...

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

A device, such as a thermionic or crystal diode, that is introduced into the vision channel of a television receiver to...

Means of correcting laser postweld shift. The correction procedure is applied to optoelectronic systems such as laser diode...

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

A piezoelectric transducer made of a thin strip of piezoelectric material bonded to a strip of metal.

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

A variable focal length lens system that retains the object in focus as one or more lenses move as a unit along its optical...

A type of fluorescence spectroscopy in which an excimer laser, a dye laser and a frequency-doubling device are used to...

A large telescope mirror fabricated from several smaller sections.

A glass substrate that has its rear surface coated with a reflective coating. Also known as a back-surface mirror.

A device used to measure the masses and relative concentrations of atoms and molecules. It utilizes the Lorentz force...

A combination of components arranged so as to perform at least one function.

A cryogenic cooler device that is an intermittent Joule-Thomson refrigerator with a passive radiator serving as the...

A defect on a polished optical surface whose length is many times its width. Block reek is a chainlike scratch formed in...

An alexandrite laser is a solid-state laser that utilizes a synthetic crystal made from the rare earth element alexandrite...

A parabolic, elliptical, hyperbolic or circular section created when a solid cone is intersected by a plane.

A spectroscope having a diffraction grating for the resolution of light of various wavelengths.

A metal, alloy or compound that loses its electrical resistance at temperatures below a certain transition temperature...

A surgical device used to deliver laser light. Specifically,contact tips are made with artificially grown sapphire which is...

A small section of the surface of a sensor corresponding to a single pixel in the image.

A viewfinder whose optical system forms a direct image of a subject, as opposed to those systems that use reflectance in the...

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

The smallest linear diameter to which a laser or other beam of radiant energy is capable of being focused, depending on the...

A diverging lens is a type of lens that causes parallel rays of light to spread out or diverge. It is thinner in the center...

A powerful and flexible machine-learning approach that can be used in machine vision to help solve difficult problems....

The Lorentz oscillator model is a theoretical model used in physics to describe the response of a charged particle (such as...

In chemistry, a halide refers to a chemical compound containing one or more halogen atoms bonded to another element. The...

Characteristic of deflected light power defined as the quadratic invariant function of the video signal amplitude.

Wave of radiation identified by individual fluctuations of electric and magnetic fields.

Also referred to as the opposition surge, the opposition effect is a photometric phenomenon in which a rough retroreflective...

A single band in a group of light and dark bands that can be viewed in the periphery of Fresnel diffraction shadow.

The wavelength at which a lamp radiates its highest intensity.

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

A property of optical fiber that results from thermal stresses during manufacturing and is defined as the amount of...

In image processing, the assigning of certain portions (or pixels) of an image a constant value of either 0 (black) or 1...

A technique for producing micron-size structures on surfaces by using short-wavelength light or electron beams.

A fundamental law of wave scattering theory that connects the extinction cross section of a scatterer to the real part of...

A system that applies a crystal as a diffracting agent to photograph the spectrum.

A dielectric ceramic material used in laser capillary tubes because of its high electrical resistivity and high thermal...

A system in which a supplied signal causes the deflection of the electron beam in a cathode-ray tube, thus forming a visible...

A camera that uses multiple exposures to record the trajectory of an ordnance from a ground-level position.

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

A scanning device used to cyclically tune through a given frequency range to determine the amplitude-frequency distribution...

In a gas, the temporary drop in density caused by contact with a sound wave.

A solid-state device similar to an ordinary transistor except that incident light on the PN junctions regulates the response...

An instrument designed to measure the proportion of light emitted by a source in the blue region of the spectrum.

The visual phenomenon of the apparent difference in the rate of motion of two objects that are actually moving at the same...

A measurement technique used for the rapid quantitative evaluation of surface quality based on the detection and analysis of...

A flanged or plain ring with a restricted aperture, located in an optical system at any of several points, that cuts off...

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

A device that permits the adjustment of facsimile transmitters and recorders so that their scanning lines stop and start at...

Increase in the diameter of an initially collimated beam, as measured in milliradians (mrad) at specified points; i.e.,...

In the context of imaging, particularly digital imaging and printing, "orange peel" refers to a texture or visual distortion...