The rotation of an instrument (or the line of sight of an optical system) in a horizontal plane; transverse.

An APD detector, or avalanche photodiode detector, is a type of photodetector used to detect light or optical signals by...

A method for remote measurement of the temperature of moving surfaces in harsh environments by using a laser to stimulate...

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

An achromat, in the context of optics, refers to a type of lens or lens system designed to reduce chromatic aberration....

The state of optically excited luminescence. Luminescence refers to the light emitted by excited atoms or ions as they decay...

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

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

The plot that expresses a reaction rate vs. the reciprocal of absolute temperature. Often used to describe the thermal...

A system that uses a continuous-wave laser to measure the velocity of an object by focusing the laser beam on the object,...

In a dual-ring local area network, a node that is connected only to the primary, active ring and not to the secondary ring...

A single number, defined by the computer program or the user that expresses the performance of an optical system. Also known...

Illumination in which the light source is imaged at the object.

An acronym for microwave amplification by stimulated emission of radiation. Predecessor to the laser, the maser or...

In television, the number of individual pixels that can be distinguished in a horizontal scanning line; also called...

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

Extremely small organic and inorganic systems of molecules within a substance. In general, systems are colloidal size in...

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

A dispersion relation defined in order to value the reciprocal amount of dispersion. It is defined as the refractivity over...

In a microscope, the physical distance between the focal points of the objective lens and the eyepiece. The standard tube...

Fluorescent proteins are proteins that exhibit the property of fluorescence, which is the ability to absorb light at a...

A laser crystal, also known as an active medium or gain medium, is a solid-state material used in the construction of...

The highest frequency at which a laser diode can be driven and still be modulated acceptably that further results in the...

Raman spectroscopy is a technique used in analytical chemistry and physics to study vibrational, rotational, and other...

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

A camera with two taking lenses and synchronized shutters. Two images are recorded simultaneously on separate frames,...

A term used to denote a difference in magnification along mutually perpendicular meridians. Anamorphic systems are basically...

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

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

A system in which the electrical signal embedded within an audio input signal is converted to a modulated light pattern and...

The ratio of the intensities of two specified spectral lines of a source having vastly different excitation energies. This...

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

An endoscope used for the visual examination of the bladder.

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

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

In sensitometric testing, a series of areas progressing by equal density steps (usually the increments between steps are...

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

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

A night-vision device that uses one or more infrared transducers to scan a scene in the 3- to 5-µm or 8- to...

The apparent difference in brightness between light and dark areas of an image. For a light target against a dark...

A portion of computer memory that is used for temporary storage of frequently accessed data. Substantially increases...

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

The multiple storage of a single image.

A laser, usually employing helium-neon or other gases as the active medium, used for alignment in industrial applications.

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

The determination of what, how much and in what proportions chemicals must be combined to produce the desired reactions and...

A system in which a sequence of direct measurements of the target position is fed into a tracking filter that may produce...

A ferroelectric polycrystalline ceramic material used in optical memories for computers and as a piezoelectric transducer.

The diagnostic procedure that uses ultrasonic energy to probe the body and, with the help of laser beams, a reflecting...

A hollow sphere coated internally with a white diffusing material and provided with openings for incident beam, specimen and...

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

A transmission electron microscope (TEM) is a powerful microscopy technique that uses a beam of electrons to create...

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

A semiconductor laser diode that emits light perpendicular to the active region. The output radiation is taken through the...

A phenomenon, exploited for medical imaging, in which the nuclei of material placed in a strong magnetic field will absorb...

A tube containing mercury vapor and lined with a phosphor. When current is passed through the vapor the strong ultraviolet...

A step-by-step method of reducing the amount of data in a digital video signal to transmit or store a high-quality image....

A two-fiber optical cable containing two single-fiber cables that are connected by a strip of jacket and that can easily be...

The control of free electron movement through the use of electrical or magnetic fields, and use of this electron movement in...

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

The visual phenomenon of the apparent difference in the rate of motion of two objects that are actually moving at the same...

Also called sine wave response and contrast transfer function. The modulation transfer function is the ratio of the...

Laser-induced fluorescence (LIF) is a spectroscopic technique that involves using a laser to excite molecules or atoms,...

A system designed to control the output quantity of a device by returning a portion of its output signal to its input. This...

An instrument for measuring reflectance.

The characteristics of a material that determine its tendency to flow.

An optical system with different focal lengths or magnification levels in perpendicular planes to the optical axis.

The stationary state of an ion, atom or molecule, above the ground state that is produced by the interaction with the...

A set of mirrors mounted on solenoids to move them into and out of the path of a laser beam, making it possible for multiple...

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

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

A thermal-infrared camera, often referred to simply as a thermal camera, is a type of imaging device that detects infrared...

An instrument designed to analyze the optical effects of color.

A rapid roughing process for the quick removal of glass, the first step in manufacture of a curved lens surface. It is...

A crystal that may serve as a diffraction grating if mounted effectively.

On a test chart, the pattern designed to direct and measure geometric distortion.

Fresnel reflection refers to the reflection of light at the interface between two different media with different refractive...

An evacuated bulb containing a tungsten filament that is heated by passing an electric current through it. In domestic light...

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

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

The removal of the zero-order component of the Fourier spectrum distribution of an object with a small, opaque absorber or...

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...

The state of a liquid crystal in which the molecules are arranged in layers with their long axes in the plane of each layer....

Defines the minimum operational standards for a self-sustaining fusion reactor as equivalence between energy released per...

The distance, on either side of the object plane focused on, through which satisfactory image definition can be obtained....

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

A device designed to detect microwave modulation and to mix modulated and unmodulated laser beams. It consists of a...

The process by which the raster beam in a video tube is cut off during the retracing and sync periods.

Raster scanning process like that of television: each line is scanned successively.

A rangefinder similar to a pair of binoculars with a long base, a dot or other wander mark provided in each eyepiece field,...

A device used in measuring the attenuation of multimode optical fibers. A short reference length of fiber when combined with...

The refraction that would take place in an idealized atmosphere where the refractive index is reduced uniformly with height...

A photovoltaic cell, commonly known as a solar cell, is a semiconductor device that directly converts light energy into...

A type of laser used when a great amount of power is required. Avoiding the bulk of large numbers of optical lenses, this...

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

A complicated constant linked with the electron theory of the Faraday and Kerr effect. It demonstrates a specific value for...

A system that consists of a spectrophotometer with a photoelectric detector for measurement of radiant energy.

The deformation of a material at high levels of stress, often associated with elevated temperatures.

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

An instrument, similar in design to regular binoculars, that can transmit and enlarge infrared images.

A substance such as a dye or pigment that is used to alter the color of light.

1. An instrument used to determine the visual range in an environment. 2. A type of photometer that artificially reduces an...

The theorem stating that, when the sampling period in a recorded sample hologram is matched to the object spectrum, the...

The combination of two waves having the same frequency and amplitude and traveling in opposite directions. Standing waves...

The process whereby the number of atoms or atomic systems in a set of energy levels is changed by the absorption of light...

A form of dispersing prism, often used in monochromators, that consists of a common right-angle prism with a 30°...

The value of the distance of distinct vision, minimum focusing distance or near point, divided by the focal length of the...

A field of physics that deals with light as if it truly were composed of rays diverging in various directions from the...

A scanning laser radar system applied to transmission and concentration analysis in three dimensions of clouds as well as...

A phenomenon that occurs in WDM and DWDM systems when three closely spaced signal wavelengths near the zero-dispersion...

An electric field produced to influence an electron stream much in the same manner that a lens affects a light beam.

The analysis and measurement of celestial bodies, their motions and positions.

That part of the science involved in the study of the theory and interpretation of spectra that uses the unique...

A type of camera that has scales or other arrangements by which successive exposures can be lined up and equally spaced on a...

A spectroscopic technique in which an excitation band absorbs laser energy resulting in an electronic transition. The...

In general, changes in one oscillation signal caused by another, such as amplitude or frequency modulation in radio which...

System of information coding in which the signal is sampled 8000 times per second and the samples quantized by referring...

A substrate refers to a material or surface upon which another material or process is applied or deposited. In various...

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

A perfect diffuser that exists only as a concept, or a white with known spectral characteristics used as a reference in...

A photodiode detector is a semiconductor device that converts light into an electrical current. It operates based on the...

A gauge designed to measure high degrees of vacuum. It consists of a glass bulb attached to the vacuum vessel, the...

For a particular mode in a waveguide, the ratio of the angular frequency to constant phase.

The circle that contains the slit, grating and primary astigmatic focus of a concave diffraction grating.

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

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

An optical illusion in which distant objects are lighter in tone and less distinct in outline than those closer to the...

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

Angular tracking measurement estimated from the properly normalized image second-moment tensor.

In plano work, that property of a surface determining that it is convex and contacts a flat test glass at its center.

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

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

The difference between the energy of an atom in its ground state and that of the same atom in its excited (quantum) state.

Material used to integrate photoconductors into electro-optical systems. It should provide low resistance to the flow of...

A fiber optic imaging bundle is a specialized optical device composed of multiple optical fibers bundled together. Each...

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

Image processing operations performed on one area of an image.

A detector and signal demodulator used in optical communications systems to receive a signal and often to translate it into...

A microchannel plate (MCP) is a specialized electron multiplier device used in various applications such as particle...

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

Fluorescence is a type of luminescence, which is the emission of light by a substance that has absorbed light or other...

A ghost image that has the reverse lightness relations of the original image. This phenomenon is a common optical illusion...

A lens derived from the Cooke triplet anastigmat, but with one of the crown elements split in two, resulting in improved...

A standard source of high-charge-state ions for accelerators that has an external magnetic field oriented perpendicularly to...

With respect to microscopy, also called dispersive staining, optical staining the projection of colors through areas of a...

Postulated by Einstein in his theory of relativity. They are waves traveling at the speed of light and exerting force on...

When applied to LCD grids, the active matrix is a means of supplying power to pixels by use of a transistor and capacitor....

An ideal body that completely absorbs all radiant energy striking it and, therefore, appears perfectly black at all...

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

A visual spectrophotometer with a rhomb located directly before the entrance aperture of a constant-deviation...

A gas laser in which the energy-state transitions between vibrational and rotational states of CO2 molecules give emission...

The basis of color vision in the human eye. Three types of cones have been identified, each having a unique spectral...

Spherical aberration is an optical aberration that occurs when light rays passing through a lens or curved optical surface...

A fast-action shutter inserted between one end of a laser rod and the end mirror; when inserted to prevent emission and then...

Chemical vapor deposition is a process of applying dopants to a glass bait by flame reactions of gaseous compounds. See also...

The polymerase chain reaction (PCR) is a widely used molecular biology technique used to amplify a specific segment of DNA...

The study and the interpretation of the infrared emittances of celestial bodies and phenomena.

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

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

Rare earth dopants refer to elements from the lanthanide series, also known as rare earth elements, that are intentionally...

The law given by the formula: that is, the frequency of radiation emitted or absorbed by a system when E2 and E1...

The process of grinding the concave surface of a single-vision spherical lens.

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

A glass that is heated, then chilled (usually by an air blast) to set up internal stresses so that the surfaces are under...

A unit of length in the metric system equal to one millionth of a meter (10-6 m). Also called micrometer. Abbreviated...

The ability of an electrical current to destroy superconductivity by means of the magnetic field generated by the current....

An electronic flash tube in which the flash recurs at a frequency extending to many thousands per second. A stroboscopic...

Two 30° prisms that are used to produce constant deviation when rotated by equal and opposite angles.

The term used in reference to vacuum systems using oil and diffusion pumps, describes the migration of pump fluids and their...

Designed for the function of optical wavefront analysis. Shack-Hartmann camera aberration sensors use a lens array to image...

Temperature of the blackbody having a spectral power distribution approximately proportional to the test source at all...

Any testing method for materials and components that does not damage or destroy the test sample. Some of the methods used...

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

A spectral line of an internal standard; used to compare radiant energy of the line being analyzed.

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

A numerical value representing the degree of contrast in a television picture: the exponent of the power law used to...

A technique used to create an achromatic phase shift based on the principle of geometric phase. The phase shift is...

A small low-power microscope or magnifier with a scale that is used to measure the exit pupil diameter and eye relief on...

Any form of laser; e.g., a dye laser, having an output that can be adjusted over a wide range of wavelengths. Normally the...

The procedure by which the similarity of an optical signal or waveform to a reference-stored signal or waveform is...

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

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

An edging stone having a relatively coarse abrasive.

Seidel aberrations refer to a set of monochromatic aberrations in optical systems, named after the German mathematician and...

An ultrafast pulsed laser is a type of laser that emits extremely short pulses of light with durations typically on the...

Of evaporative coatings, a condition resulting when small chunks of material fly from the hot crucible onto the substrate...

Image displacement by a decentered lens, rotated on a chuck whose axis of rotation passes through the geometrical center of...

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

Optical glass containing zirconium fluoride that results in special characteristics such as improved transmission.

CoaXPress (CoaXPress or CXP) is a standardized digital interface and communication protocol used primarily in machine vision...

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

In hybrid or monolithic integrated circuits, the laser ablation of a portion of resistor material to achieve the design...

A nonlinear crystal used to modulate a polarized beam of light by means of the Pockels effect. A Pockels cell is used as a...

Literally, neodymium:yttrium-aluminum-garnet. A cylindrical rod of yttrium-aluminum-garnet doped with neodymium that is the...

The limitation on performance imposed by the distortion of a received signal rather than its amplitude or power.

A substance that transmits the infrared, but which is too delicate or fragile to be used in the form of a single crystal....

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

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

Dispersion refers to the phenomenon where different wavelengths (colors) of light travel at different speeds when passing...

The system of color classification and description produced by Wilhelm Ostwald.

The longest wavelengths of the ultraviolet region, nominally 300 to 400 nm.

An old name for the rotating arm moving about an axis of rotation over a divided circle used to measure angles. Now the term...

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

A machine vision lens is a specialized optical lens designed for use in machine vision systems, which are used for automated...

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

The use of a surgical laser instead of sutures or staples to close a wound or rejoin severed blood vessels.

Designating any instrument in which both eyes can be used to view the image to achieve a stereoscopic effect, or merely to...

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

A photon-counting instrument for use in both space-borne and ground-based photometric and spectroscopic instrumentation....

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

1. In a photonic interconnect, the number of detectors in a given area. Detectors spaced too closely may give rise to...

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

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

A formula indicating that, for an imaging lens system, the image brightness for off-axis points will fall off at a rate...

The discernment of depth or apparent difference in distance that causes the object to stand out from its background because...

The photographing of a scene from positions corresponding to the locations of both eyes. A viewing device is used to present...

Naturally occurring planes in crystalline substances that provide easy points for separation.

A testing device that provides a contour map of the emergent wavefront for the observer in terms of the given wavelength of...

An instrument designed to measure the index of refraction of a gas by the interference patterns formed by two beams, one of...

A unit of luminance that is equal to one candela/cm2. (sb).

A printing process of electrostatic electrophotography that uses a photoconductive insulating medium, in conjunction with...

A statistical method of dealing with a series of values where each value is squared, the mean of these squares is...

MicroRNAs (miRNAs) are a class of small, single-stranded RNA molecules, typically consisting of about 19 to 24 nucleotides,...

A photodetector in which an electrical charge is produced when incident photons change electrons within the detecting...

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

A camera equipped with a lens and a long length of perforated film, the latter being moved intermittently between exposures...

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

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

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

A device used to measure the intensity of radiant energy.

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

Bohr's formulation that every new theoretical principle must correspond to the salient classical predecessor. The principle...

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

That distortion resulting from dispersion of the group velocity of a propagating mode. It is the only distortion occurring...

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

In image acquisition (and sampling theory), the postulate that the pickup sampling frequency must be a minimum of twice as...

An approach to optical character recognition based on matching the input character against a set of stored prototypes.

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

A laser oscillator in which two mirrors are separated by an amplifying medium with an inverted population, making a...

Gallium nitride-based light-emitting diodes (GaN-based LEDs) are semiconductor devices that emit light when an electric...

The code used to describe the United States system of color telecasting.

A light filter that equally decreases the intensity of all wavelengths of light without altering the relative spectral...

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

An optical fiber in which the core is of uniform refractive index.

Instruments used for measuring angles and occasionally lengths on the ground. The principal surveying instruments are the...

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

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

The properties exhibited by a semiconductor as the result of its modification by imperfections and impurities in the crystal.

In colorimetry, the phenomenon in which spectrally different radiations produce the same color sensation for a given...

A laser that uses a substance in the liquid state, such as an organic dye, as the active lasing medium.

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

Label-free refers to a technique or method that does not require the use of additional labels, tags, or markers to detect or...

A lens assembly made up of three lens elements that may or may not be cemented.

An aspheric lens is a type of lens whose surface profiles deviate from the traditional spherical shape. Unlike spherical...

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

A fiber optic bundle split along its length with the ends of the fibers extending separately to illuminate different points...

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

The eye's involuntary reaction in the process of accommodation. This reflex is most dramatic in response to looking at a...

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

A superthin, highly reflective mirror.

Parallel scanning refers to a method of acquiring data or images simultaneously from multiple sources or in parallel, rather...

A specific, right-angle prism having a transmission grating replicated on its hypotenuse face and used in applications...

A method of manufacturing polycrystalline infrared-transmitting optical fiber by heating a single halide crystal billet and...

Ferroelectric materials are a type of dielectric materials that exhibit spontaneous electric polarization, meaning they...

Nanoparticle photonic resonator absorption microscopy is a microscopy technique that combines the principles of photonic...

Characteristic of an object so small in size or so fine in structure that it cannot be seen by the unaided eye. A...

A type of laser for which a large number of the components can be fabricated in or upon a single substrate.

A CMOS image sensor, short for complementary metal-oxide-semiconductor image sensor, is a type of semiconductor device used...

The suppression of fluorescence by absorption of the stimulating radiation.

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

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

An instrument used for video or computer data storage in which a laser optical head is used to write digital information...

A PIN photodiode is a type of photodetector or semiconductor device used to convert light signals into electrical signals....

A sheet of plastic material containing microscopic crystals of herapathite or some other similar substance that transmits...

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

A term variously applied to remote sensing techniques that essentially refers to all parametric conditions that influence...

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

Epitaxial refers to the growth of a crystalline layer on a crystalline substrate in such a way that the orientation of the...

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

A host crystal for chromium that emits pulsed or continuous-wave laser light, tunable from about 720 to 790 nm.

In the SI system, prefix meaning one-thousandth, 10-3.

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

A resonator often used for mode control in Fresnel number laser cavities that is highly vulnerable to extremely weak...

1. In detector technology, the long wavelength at which detector response falls to a set percentage (usually 20 or 50...

Formulas designating the relationships between image distance, object distance, focal length, refractive index, etc., of a...

A ray of an image-forming bundle that passes through the edge of the entrance pupil or aperture stop. Usually used in...

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

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

With respect to a crystal, having three unequal axes intersecting at angles, only two of which can be equal and only one of...

The electrical resistance between two points of a conductor when a constant difference of potential of one volt, applied...

Ion-beam sputtering (IBS) is a physical vapor deposition (PVD) technique used for depositing thin films onto substrates. It...

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

The central portion of the retina that has the greatest sensitivity to form and color.

A waveguide is a physical structure or device that is designed to confine and guide electromagnetic waves, such as radio...

A periodic structure formed by intersecting or superimposed laser beams. These beams can trap atoms in low-potential...

Radiation in which every ray from any given object point can be considered to be parallel to every other. This is never...

A substance that increases a material's sensitivity to electromagnetic irradiation. In photodynamic therapy, a drug used to...

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

A special-purpose polarimeter having a scale calibrated directly in the concentration of sugar in the test solution.

A single-particle scattering technique in which an incident laser beam is tightly focused by means of lenses to yield a...

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

In data communications, the simultaneous operation of a circuit in both directions is known as full duplex; if only one...

An otoscope is a medical device used by healthcare professionals, particularly ear, nose, and throat (ENT) specialists,...

Founded by professor Albert Munsell. In the field of colorimetry, the Munsell color system is a color space that identifies...

The creation of a diode laser structure by liquid-phase epitaxy over a grooved substrate.

A phototube having a cesium-coated cathode that has its greatest sensitivity in the infrared region.

Thin layers intended to prevent damage to plastic optics.

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

In an optical system, noise created by mode-dependent optical losses and variations in the distribution of radiant power...

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

An electronic transducer, either fixed or adjustable, that reduces the amplitude of a wave without causing significant...

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

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

A factor that, when multiplied by the average candlepower emitted by a light source in a specified angular zone, reveals the...

An optical part constructed of a single piece of optical material. It is usually a single lens, prism or mirror.

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

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

The computer module whose circuitry interprets instructions and guides the actions of the peripherals. Also known as the...

That angle found between a pair of adjacent faces of a crystal.

In a crystal, its subdivision into polyhedral blocks of macroscopic sizes, with discontinuities contained in the lattice...

A compound prism formed by cementing together two 30° prisms, one of right-handed and one of left-handed quartz. It has...

A graduated range of stimuli perceived as having equivalent differences of brightness.

Measurement of a translation stage's deviation from absolute straightness, that is, its angular motion in both the vertical...

A casting consisting of an optical material molded into the desired geometry for grinding, polishing or, in the case of...

A plate consisting of fused optical fibers with both surfaces ground and polished, and having the entrance surface curved to...

A characteristic of optical fiber used to calculate the fiber's ability to maintain polarization. The beat length describes...

The maximum number of users who are using a given communication channel. Typically, the number of users at any given time is...

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

A type of comparator with a telescope equipped with a cross wire mounted on a vertical sliding column. It is used to measure...

Plasma's ability to stop the transmission of laser light.

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

An optical assembly refers to a collection of optical components that are carefully arranged and aligned to perform a...

A simple electrostatic lens with a focus controlled by a single potential difference.

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

Measures by heterodyning interferometry the local slope of a vibrating sample. The method allows the reconstruction of a...

An enzyme-linked immunosorbent assay (ELISA) is a laboratory technique used to detect and measure the presence of specific...

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

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

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

1. A lens situated at or near the plane of an internal image to project the aperture of a previous objective or erector upon...

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

Vision in depth of three dimensions as a result of the spacing of the eyes. This spacing allows the eyes to see objects from...

Of or pertaining to the methods of the French philosopher Rene Descartes. Refers to the standard orthogonal X-Y-Z coordinate...

A traveling microscope or an automatic microdensitometer used to measure the spectrum plate obtained in a spectrograph.

A polarizing prism consisting of two calcite prisms cemented such that they deviate the two emerging beams (which are...

A system incorporated into fiber optic data communications characterized by several spatially distributed terminals that are...

A two-stage illuminating system for a microscope in which the source is imaged in the aperture of the substage condenser by...

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

A V-shaped channel pressed or etched into a substrate, in which, for example, optical fibers may be placed to create an...

A device used to detect elevation, pyramid and resolution errors in prisms and other components by bringing them into...

A piezoelectric transducer made of a thin strip of piezoelectric material bonded to a strip of metal.

A Darlington current amplifier consisting of two separate transistors, of which a phototransistor is the input device.

The emission of a photon by the return of an excited carrier from the conduction band to the valence band of a semiconductor...

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

A fiber-coupled photoconductive antenna (FCPA) is a type of optoelectronic device that combines a photoconductive antenna...

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

An antigen is any substance that is capable of triggering an immune response in an organism. Antigens are typically proteins...

Circular dichroism (CD) is a spectroscopic technique used to study the structural characteristics of chiral (asymmetric)...

Lens testing equipment refers to a range of specialized tools and instruments used to evaluate the optical performance,...

Refers to a variety of methods and tools used to determine the surface contour and performance of optical components and...

The angle at which photoelectric sensors are aligned to prevent light from being reflected back to the sensor from the...

A spectrophotometer in which the beam emitted by the radiation source is split into beams that travel through the sample and...

A highly accurate cathode-ray tube used to display information with the utmost efficient stability and resolution. The...

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

An instrumental technique that utilizes the mass-to-charge ratio of charged particles as recorded from a mass spectrometer...

A device, such as a thermionic or crystal diode, that is introduced into the vision channel of a television receiver to...

A precision lens designed to convert the plane wavefront output of an interferometer to a spherical wavefront for the...

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

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

Superresolution refers to the enhancement or improvement of the spatial resolution beyond the conventional limits imposed by...

Focal, nodal or principal points of a lens. If the respective distances of the object and image are measured from the...

An instrument designed to give a visual indication to the pilot when the plane has strayed from a specific flight path.

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

An instrument for determining the sensitivity of a photographic film to light. The film is given either a stepped exposure...

A defect of natural quartz crystals in which both the right and left quartz are in the same crystal.

Also referred to as the axial ray (or a-ray), a marginal ray originates from the axial point of the object and passes...

A thermistor that uses a semiconductor that is sensitive to infrared radiation to measure the radiation's intensity.

A closed-loop system that is constantly adjusted in response to input signals generated within the system.

An instrument usually consisting of a very long interferometer, 3 to 800 m, and a laser light source for the study and...

A crystal-based device that combines and adjusts the intensities of multiple wavelengths of laser light in order to obtain...

An instrument used to measure the change of heat content of a system by measuring microwave power in terms of generated heat.

The method used to determine the refractive index of a given substance.

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

In a microscope, the diaphragm located between the Bertrand lens and the eyepiece, which is closed during conoscopic viewing...

That wavelength at which the absorption of a given element or system begins to demonstrate an inconstant value.

This results from the simultaneous absorption of two photons, each having half the energy needed for excitation and...

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

Sparkling granular pattern that is observed when an object diffusely reflects coincident laser light. Speckle appears as an...

Thermophotovoltaic (TPV) refers to a technology that converts heat energy into electricity using the principles of...

A device, either visual or electronic, that emits signals to identify set positions for use in the navigation of aircraft...

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

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

The ratio of the first focal length of a lens to the refractive index of the medium containing the incident light; the ratio...

Any instrument or system carried by a balloon to the upper atmosphere to measure and record atmospheric information, such as...

Optical design and engineering services involve the development, customization, and optimization of optical systems and...

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

The space between diffracting centers of an ultrasonic wave that is forming certain light diffraction spectra.

Image distortion that occurs when the axes of the original image are not perpendicular in the resulting image, making the...

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

In a symmetrical optical system this is a measure of the influence of the system upon the focus of a pencil of rays passing...

A method for obtaining the optical absorption spectra of solids, semisolids, liquids and gases. PAS is inherently...

An impurity-doped silicon detector array sensitive to long infrared wavelengths, installed in optical collecting systems...

An instrument designed to measure the rate of rotation of components, such as shafts.

An electronic tube instrument in which the anode current varies with the intensity of light incident on the cathode.

With respect to a traveling plane wave at a known frequency, the space rate of decrease of phase of a field component in the...

A technique for measuring fiber attenuation or distortion by performing two transmission measurements. One is at the output...

A single long gate electrode that transfers the line of charge packets to the transport shift register in a charge-coupled...

A material consisting of very small colorless particles imbedded in a clear glass matrix. It is available in two forms:...

Flow cytometry is a powerful technique used in biology and medicine for the quantitative analysis of the physical and...

A collector for photovoltaic power generation that consists of a thin plate that strongly absorbs sunlight striking its...

Ultraviolet reflectance refers to the ability of a material or surface to reflect UV light. Ultraviolet light is...

A variation of tomography in which several photographs of a patient are taken at different angles, and back-projection of...

A device designed to convert linear change in the light state at input to log data at output.

Photocells of various kinds used to measure photometric quantities; i.e., intensity, luminance and illuminance. Meter...

Fine lines, wires or threads used in the focal plane of many optical instruments to point out and locate particular objects...

Deformation of a material caused by mechanical factors, especially constant pressure, and not attributable to thermal...

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

A diode-pumped solid-state laser (DPSSL) is a type of laser system that uses semiconductor diode lasers to pump energy into...

1. In astronomy, the angle measured clockwise (eastward) in a horizontal plane, usually from north (true north, Y-north,...

Ability of a laser to resist variations in output power caused when it is slowly rotated about its optical or symmetrical...

A positive after-image that is maintained for a minute or more.

A modulator is a device or component that modifies a carrier signal in order to encode information for transmission over a...

Optical character recognition (OCR) is a technology that is used to convert printed or handwritten text into...

A digital camera is a device that captures and records still images or video in digital format. Unlike traditional film...

A two-mirror lens design used in astronomical telescopes, the primary being a parabola, the secondary a smaller hyperbola....

The phenomenon whereby certain crystals exhibit spontaneous electric polarization. It is analogous with ferromagnetism.

Pixel pitch refers to the distance between the centers of two adjacent pixels on a display screen or imaging sensor. It is...

The measured wavelength of the most distinct edge of a spectral band.

Proportions of standard primaries (tristimulus values) required for a color match; ratios of each tristimulus value of a...

The nonthermal conversion of electrical energy into light in a liquid or solid substance. The photon emission resulting from...

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

An instrument that is used to detect high-energy particles by the pulse of the current formed when a particle passes through...

Ray tracing is a rendering technique used in computer graphics to simulate the way light interacts with objects in a scene....

The fringes used in the Jamin interferometer and produced by light that has been internally and externally reflected by two...

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

In laser welding or heat treating, the instantaneous laser beam power per unit area. This parameter is key in determining...

A fiber optic transceiver, often simply referred to as an "optical transceiver," is a device used in fiber optic...

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

An electrical problem that occurs when voltage is not the same with respect to ground at every node of a system, causing...

An atom that has gained or lost one or more electrons and, as a result, carries a negative or positive charge.

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

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

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

In optics, an image is the reconstruction of light rays from a source or object when light from that source or object is...

An image tube that functions in low-light-level conditions by virtue of its series of stacked sections wherein the output of...

In an optical system, the aperture size at which the lens gives its best overall performance.

A binary code with two information states (1 and 0) and no neutral state between bits.

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

A lamp that has mercury in a tube or bulb that has first been evacuated. The electricity travels through the vapor between...

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

The imaginary line passing through both the centers of curvatures of the optical surfaces of a lens or mirror; the optical...

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

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

A system of local area networking in which each node or station is connected to two others, ultimately forming a loop. Data...

An instrument for detecting or measuring small electric currents.

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

A measure of the closeness with which an optical image is capable of resembling the original object. The factors that affect...

A vacuum tube with an electron gun at one end and a fluorescent screen at the other. Electrons emitted from a heated...

A test used to measure the degree of fading of different colored materials, especially those involving organic dyes, which...

Nondestructive measurement of the delta and alpha of clad optical fibers that involves interferometry with the fiber...

A device consisting of a disc with a spiral arrangement of holes that is used to convert visible patterns into electrical...

A mixed-signal oscilloscope (MSO) is a type of electronic test instrument that combines the capabilities of both a...

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...

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

A formulaic description of the linear change of the reciprocal optical dielectric tensor with either stress or strain.

A CubeSat is a type of miniaturized satellite characterized by its standardized size and modular design. CubeSats are...

Developing a photographic image by means of an applied electric field. The methods used include electrolysis and...

A lamp that emits light when an electric current passes through a resistant metallic wire situated in a vacuum tube.

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

A facility selected by mutual agreement of the user and the prospective vendor to test a prototype before it is offered for...

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

The altering of lightwaves by acoustic waves in a solid medium.

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

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

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

A charged elementary particle of an atom; the term is most commonly used in reference to the negatively charged particle...

An apochromat, often referred to as an apochromatic lens or apochromatic objective, is a type of optical system designed to...

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

A solid-state device, composed of silicon, that is used to convert radiation into electrical energy.

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

Liquid crystal on silicon (LCoS) is a display technology that combines liquid crystal materials with silicon-based...

An instrument used to detect and measure radiant energy by the formation of a chemical reaction.

A reflecting prism that is rhomboidal in shape. It has two parallel transmitting faces, and two parallel reflecting faces;...

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

A high-speed cine camera that produces discrete frames of a continuous event as opposed to the flow photographic record of a...

A reticle, also known as a reticule or graticule, is a pattern or set of markings placed in the focal plane of an optical...

An optical device that permits the alignment of a gun, cannon or rocket launcher system with its target.

In an optical waveguide,- typically a multimode fiber - the distortion resulting from differential mode delay, i.e. axial...

A lens, usually having one or more cylindrical surfaces, used to produce distorted images and later to restore them to true...

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

An imaging technique in which an object moving through an interference field formed in space scatters light and is spatially...

A crystal having identical lattice points.

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

In physics, the law of reversibility is often associated with the concept of reversibility in thermodynamics. The law...

Interval between cutting off a photoconductor's signal and the fall of current output to 90 percent.

An apparatus, designed for use with a camera, that is used to rapidly open the path from lens to film, to maintain the...

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

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

A powerful method, referred to as FCS, for determining the average diffusion coefficients of fluorescent molecules in...

Refers to the transistors in which the working current flows through only one type of semiconductor material, either P-type...

A quarter- or half-wave retarder made from two plates of quartz, mica or polymer with their fast axes crossed; the...

An embossed or marked disk, constructed out of a transparent material and used with a camera system to soften an image.

A spatial light modulator consisting of a metallized polymer film stretched over an array of metal-oxide semiconductor...

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

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

A double meniscus system in which two achromatized meniscus lenses are arranged symmetrically on either side of the aperture...

That branch of science involved in the study and utilization of the motion, emissions and behaviors of currents of...

Augmented reality (AR) is a technology that integrates digital information, typically in the form of computer-generated...

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

A camera that consists of a concave spherical mirror with an aspheric plate situated at the center of curvature of the...

Whispering gallery mode (WGM) refers to a phenomenon in wave physics, particularly in optics, where waves, such as light or...

A beam of light whose electrical field amplitude distribution is Gaussian. When such a beam is circular in cross section,...

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

A measurement technique used to determine the spatial distribution profile of an electrical or optical quantity of interest...

A compound lens consisting of two negative lenses of flint glass. A double-convex lens of crown glass is cemented between...

A contour mapping technique that involves projection of a grating onto an object to produce a shadow grating that is...

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

An array of refractive microlenses that are round, square and hexagonal and as small as 15 µm. They are used for...

A unit of length in the metric system equal to 10-9 meters. It formerly was called a millimicron.

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

High-voltage, fast-discharge circuit named after its inventor, Erwin Marx. Its capacitors are charged in parallel and...

Also known as radiation thermometer. A pyrometer in which the radiant intensity from the source to be measured is used to...

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

An optical matrix that does not require perfection in both states of the crosspoint, so that all the optical switches can be...

A form of liquid crystal in which flow does not take place in the usual manner. When examined with polarized light, the...

The degree to which a pair of fine lines can be aligned to each other. A normal observer will demonstrate an accuracy of 10...

Also known as constant angle or constant deviation fringes. The interference fringes observed with dense flat plates near...

A device that is designed to automatically turn electric lamps on and off in a rapidly repeating sequence. The device may...

Hypothetical observer having standard color vision as described by standard color-matching properties.

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

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

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

Induced pluripotent stem (iPS) cells are ordinary cells that are genetically reprogrammed to an embryonic stem cell-like...

In considering a field of electromagnetic energy emanating from a source, the wavefront is a surface connecting all field...

A GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic...

A bench photometer that depends on the inability of the eye to distinguish color in brief flashes of light. Any difference...

That part of the cladding wherein the refractive index is constant within a specified tolerance, as a function of radius.

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

The spectrum formed by a dispersing prism or a dispersing prism system.

In the context of electronics and semiconductor manufacturing, a wafer refers to a thin, flat disk or substrate made of a...

A Mach-Zehnder interferometer is an optical device used to measure the phase difference between two collimated beams of...

1. In a plane Cartesian coordinate system, the horizontal axis, or axis in the left to right direction. 2. In a quartz...

The real part of the axial propagation constant for a particular mode. The attenuation coefficient for the mode power is...

The chromatic resolving power of a prism is invariably stated for the case in which parallel rays of light are incident on...

An electron tube that is used as a camera tube for a television system. When the picture to be transmitted is focused on a...

A beamsplitter is an optical device for dividing a beam into two or more separate beams. A simple beamsplitter may be a very...

Hardware installed on fiber cable ends to provide cable attachment to a transmitter, receiver or other cable. Usually a...

A magnetic-deflection mass spectrometer that has an electrostatic field placed perpendicularly to its magnetic field,...

Hydrophilic is a term used to describe substances or materials that have an affinity for water. The word hydrophilic comes...

In the dye laser, the molecule that takes out energy from the triplet state during collisions between the dye and quencher...

Retroreflection is a phenomenon in optics where light is reflected back toward its source, typically in a direction nearly...

A particle that will not normally diffuse through animal or vegetable membrane. Larger than most inorganic compounds,...

A binary semiconductor compound used as a substrate or active layer for diode lasers.

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

The central peak (including everything interior to the first zero or dark ring) of the focal diffraction pattern of a...

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

An eyepiece combined with an erecting prism or lens system.

A cell filled with a transparent material that, when placed in a strong electrical field, exhibits double refraction. Since...

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

A device (e.g., prisms, lenses, tubes) used to align a beam in a system.

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

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

A noncrystalline, inorganic mixture of various metallic oxides fused by heating with glassifiers such as silica, or boric or...

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

Abbreviation of "synchronization.'' In television, the timing signals used to drive the scanning process. Horizontal...

A defect in an optical system that prevents rays from reaching their intended destination; it can be caused by an undersized...

A standard for fiber optic data transmission systems being developed by the American National Standards Institute (ANSI) and...

Solar regions characterized by low density and open magnetic fields where high-speed solar wind streams originate....

A quantitative measurement of the coherence of a light source; equal to the visibility (V) of the fringes of a two-beam...

1. The value on either the leading or the trailing edge of a laser pulse at which the power is one-half of its maximum...

A device for measuring linear dimensions. The optical caliper generally consists of two circularly mounted mirrors whose...

Intravital microscopy is an imaging technique used to visualize biological processes within living organisms, typically in...

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

A technique for detecting free radicals by their electronic spectra. The material to be studied is placed in a...

A convex, concave or flat cast iron form that is used to shape a soft mold block of optical components.

A test method for determining high-reflectivity levels by monitoring cavity decay within a resonant cavity formed by two...

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

A magnon is a quasiparticle representing a quantized spin wave in a magnetic material. In other words, it is a collective...

A liquid crystal display using the material in its supertwisted nematic phase; the birefringence of the liquid crystal...

The soft x-rays used in the industrial radiography of materials having too small a range of densities to produce an image...

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

Nd:YAG laser refers to a solid-state laser that utilizes neodymium-doped yttrium aluminum garnet (Nd:Y3Al5O12) as the gain...

The sunlight that extends to the earth after scattering from other solar bodies, mostly from meteorite dust of radii...

1. Voltage at which a PN junction begins to pass a current. 2. In a solid-state lamp, the voltage at which light is first...

An instrument used to detect radioactive materials: alpha particles or helium nuclei; beta particles or free electrons; and...

A technique in which a beam of x-rays is directed against a crystal, the atoms of which, because of their lattice...

Characteristic of optical analyses that are limited to infinitesimally small apertures. Also called first-order or Gaussian...

A device that acquires a signal and then stores it for a specified period of time before processing, and used, for example,...

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

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

A device used for the comparison of spectra used, in turn, for the comparison of elements, such as the absorption lines in...

An acid used to etch the surfaces of particular materials. For glass, hydrofluoric acid is used either as a liquid or a...

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

An optical projection device designed to project positive color transparencies onto a screen for viewing.

A system that uses infrared detectors and related instrumentation to determine when abnormal amounts of infrared radiation,...

Spectral domain optical coherence tomography is an imaging technique used in medical diagnostics, particularly in...

The unequal angular velocities of two objects moving at equal speeds but at different distances from the observer, which are...

One of a class of crystalline substances belonging to triclinic, monoclinic and orthorhombic systems that have two optic...

The area closest to an aperture or source where the diffraction pattern differs substantially from that observed at an...

A phosphor that has the ability to convert into light emission a portion of energy lost by ionization when a charged...

An event-based image sensor, also known as a dynamic vision sensor (DVS), is a type of digital imaging device designed to...

The first-order spectrum formed by a diffraction grating.

A television system that does not broadcast television signals but transmits them over a closed circuit.

A system that determines whether an image is in or out of focus by means of a source of illumination at the conjugate focal...

Method for reducing laser speckle in which the object field comes from a real diffuse object or the reconstructed object...

A unit that converts images to the standard NTSC format for use with video recorders, projectors and discs.

A camera that permits adjustments in the perspective of an image; this is accomplished by the camera design, which permits...

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

A transducer is a device or component that converts one form of energy into another. It is commonly used in various fields,...

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

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

The presence, within the body of the glass, of extraneous or alien material. See seed; striae.

An exposure meter that indicates the amount of light reflected from the subject of interest.

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

A type of fatigue found in optical fibers, caused by water or another corroding agent.

A lens is a transparent optical device that focuses or diverges light, allowing it to pass through and form an image. Lenses...

On the CIE chromaticity diagram, the distance from the achromatic point to the sample point, divided by the distance from...

Flow chemistry, also known as continuous-flow chemistry, is a chemical manufacturing process where reactions take place in a...

A surgical procedure for correcting vision by reshaping the outer surface of the cornea through the use of a laser system.

The rays (such as ultraviolet rays) lying past the visible region of the spectrum.

The image of the aperture stop, usually the objective lens, that is produced by the eye lens. When the exit pupil of the...

A material used to jacket fiber optic cables. It is chemical- and moisture-resistant, but not fire-resistant.

That invisible region of the spectrum just beyond the violet end of the visible region. Wavelengths range from 1 to 400 nm.

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

An optical system used to collect infrared energy from a scene using scanning optics with a point or line detector, as...

The pattern, formed by a character generation cathode-ray tube system, in which the characters are made up of wave shapes...

A photomask, also known simply as a mask or reticle, is a key component in the photolithography process used in...

In photonics, a lattice refers to a periodic arrangement of optical elements or structures, often on a microscopic or...

A thermal infrared imaging procedure developed for quality control of printed circuit boards. The thermogram of each board...

A plasma accelerator is a type of particle accelerator that uses electric fields and magnetic fields to accelerate charged...

Calculation of gas and aerosol transmission and emission characteristics for several model atmospheres, including two model...

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

A camera system used for microphotography in which the document to be recorded is on a flat bed, perpendicular to the lens...

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

Phase contrast microscopy is an optical microscopy technique that enhances the contrast of transparent and colorless...

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

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

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

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

Rockwell hardness (Rc) refers to a method for measuring the hardness of a material, primarily metals, using an indentation...

Also known as gatling gun laser. A system that has an array of lasers sharing a common central axis on a rotating Fabry...

The detection and analysis of naturally formed extraterrestrial electromagnetic radiation within the radio frequency range...

Any crystalline material whose length is much less than its measured diameter.

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

Surface analysis by means of photon induced electron emission. PEM methods provide high lateral resolution of the observed...

Design and engineering consulting services refer to professional services provided by specialized firms or individuals to...

The total optical power loss in a system. The loss budget is often stated in terms of the transmitted power and the power...

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

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

An instrument in which visible light beyond the critical angle from a metallurgical microscope is focused on a reference...

The photographic recording of images produced by the electrons from an electron microscope. The electron beam carries the...

A device to modulate spatially a collimated coherent beam of light with input data in optical data processing. It uses a...

A method of measuring distance by recording a single scene from two points of perspective. Surveying instruments can be...

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

The third dimension (depth or Z-axis) in an imaging system.

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

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

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

The term light field refers to the spatial distribution of light rays traveling in all directions through a given space. It...

An optical instrument containing a gimballed sighting telescope, used to measure angular relationships in horizontal and...

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

A method of coding image data by storing in memory only differences in brightness of each pixel from that of its nearest...

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

Any structure having the ability to guide the flow of radiant energy along a path parallel to its axis and to contain the...

In the context of imaging, particularly digital imaging and printing, "orange peel" refers to a texture or visual distortion...

That property of certain optical devices, e.g., a penta prism, that maintains the angular relationship between the entering...

The process by which laser emission is used in measuring fluid velocity and, more specifically, the detection of air and...

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

Micro-optical coherence tomography (micro-OCT) is an imaging technique that is an adaptation of optical coherence tomography...

In an ionic crystal, the region in the crystal lattice where the ion, predicted to be present, is absent.

A telescope lens is a primary optical component of a telescope system that gathers and focuses light to form an image. It is...

The introduction of a filter into an imaging system to implement a phase contrast for an intensity mapping of a pure phase...

A device used to delay transmission of a signal for functions such as memory loops, sequential processing or built-in...

The investigation of microstructures by an instrument that generates a narrow, highly collimated beam of x-rays.

A device used to take turbidimetric or nephelometric measurements by considering the contrast between a constant brightness...

An instrument that divides a single laser beam in two and uses one half as a sensing beam and the other as a reference beam,...

A plastic used in molded optical components. Styrene elements can be combined with acrylic elements to produce achromatic...

In the SI system, prefix meaning 1015.

With respect to microscopy, light that is directed through the specimen by a substage condenser.

A hologram formed by the recording of a plane object situated in the focal plane of a lens so that each object gives rise to...

The storage of information via optical means, primarily employing a low-power laser to inscribe data on a photosensitive...

A high-power riflescope specifically intended for sighting and shooting distant targets.

In a silicon photodiode, the dynamic resistance (dv/d1) of the junction at zero volts.

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

Solar radiation intensity existing in free space at the mean solar distance of the Earth. Commonly expressed in g cal...

This type of miniaturized system, referred to as CMOS qPCR, combines microfluidic technology with an ultralow-light CMOS...

An advanced magnetic device used in x-ray lithography to beam x-rays onto the surface of silicon wafers used for...

White, tetragonal crystals used in the production of luminous coatings.

The ability of a conductor to store an electrical charge; its value is given in farads as the ratio of the stored charge on...

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

An instrument that uses an erbium:glass laser to determine cloud height from the ground.

A multifaceted holographic disc that is rotated by a motor to deflect incident light to a scanning system's lens.

Integration time, in the context of optics, imaging systems, and sensor technology, refers to the duration over which a...

Second-order nonlinear optical properties refer to a class of phenomena exhibited by certain materials in response to...

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

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

A system used for measuring direct solar radiation.

A camera with a very high aperture lens or mirror system for photographing x-ray fluorescent screen images, mainly to save...

A mirror used to manipulate the beam in a laser system.

An optical wedge of very small angles that admits light while sealing out moisture and dirt and that may be rotated to...

A dielectric sphere with an index of refraction that varies with distance from the sphere center. A parallel beam of rays is...

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

An alteration in magnification from the center of the field to any point in the field, measured in a radial direction from...

There are three types of telecentric lenses: -Image-space telecentric lenses are those in which the aperture stop is...

A technique proposed for studying the atomic structure of crystals by measuring the interference pattern generated when the...

That plane in an optical system containing its optical axis and the chief ray. Also called the tangential plane.

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

Ultraviolet-C (UV-C) refers to a specific range of ultraviolet radiation with shorter wavelengths than those of visible...

Continuous conversion of oscillatory energy into heat, relative to time or distance.

The effect, present in particular phosphors, that is defined as a transformation in the dielectric constant of a material...

1. In fiber optics, a protective material applied as an optical fiber cover that has no optical function. 2. In image...

An optical waveguide having a silica core and a plastic cladding.

In the SI system, prefix meaning 1012. (T).

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

In an optical rangefinder, the system of wedges that rotate in opposite directions to aid in the detection of deviation in...

A ground-based navigation beacon that emits pulsed signals which are picked up by aircraft making an instrument (blind)...

A form of liquid crystal in which the 90° twist of the twisted nematic phase has been increased to 180° or more,...

The element in a charge-coupled device that receives the charge packets transferred from the line of sensor sites and then...

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

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

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

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

The creation of a chemical reaction in a substance when radiation is directed to it.

The use of a variable transmission filter at the aperture stop of a lens to modify its diffraction pattern. Reduced...

A specific gas-filled tube designed to illustrate the luminous effects of discharges through rarefied gases.

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...

With respect to color photography, the measurement, at a given wavelength, of the way the color film modulates the radiant...

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

The formation of a distinct, irregular surface pattern on a photographic emulsion due to differential swelling of the...

A method of data multiplexing that can provide large, instantaneous bandwidths for busy traffic while permitting slow...

Straight line travel. This denotes the fact that light travels in a straight line when traveling through a medium with a...

A laser fitted with up to eight optical fibers that transmit the energy to different workstations in turn.

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

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

The size of the field of view in the object space of an optical system as differentiated from that in the image space...

A coherent fiber bundle (CFB), also known as a coherent fiber optic bundle, is an assembly of multiple optical fibers...

Attenuation refers to the gradual loss or reduction of intensity, force, or magnitude of a particular property as it...

In a laser, the series resistance necessary for a stable electrical discharge.

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

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

The organic inclusion in quartz crystal that forms delicate films and microspheres and that shows a maximum absorption at...

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

Relative to radiation wavelength, the law that states that the wavelength of luminescence stimulated by radiation always...

Study of the reflection or transmission properties of specimens as a function of wavelength.

The use of head-mounted displays and body-operated remote actuators to control distant machinery. Provides a virtual...

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

The angle subtended by an object, determined by the size of the object and its distance from the viewer.

An atomic force microscope (AFM) is a high-resolution imaging and measurement instrument used in nanotechnology, materials...

Made up of four elements; for instance, gadolinium, scandium, gallium and garnet (GSGG).

The span of frequencies within which a single channel of broadcast television must fall; in the US, it is 6 MHz.

Optical cements and adhesives are specialized materials used in the assembly and bonding of optical components in optical...

A molded lens is an optical lens manufactured using a molding process, typically involving the shaping of a material, such...

The distortion in an ophthalmic lens resulting from the refraction of light rays entering the periphery of the lens surface....

One or more spots placed in the field of view of an optical system to provide a means of reference.

Meta-optics, also known as metasurface optics or flat optics, is a branch of optics that involves the design, fabrication,...

A resonator is a device or system that exhibits resonance, which is a phenomenon that occurs when an external force or...

A specific method for measuring the diameter of irregular shaped particles, Martin's diameter is the measured distance...

Operation in which the minimum detectable signal has its limits set by the thermal noise of the detector, the load...

In television, the period during which the electron beam is cut off while the raster returns from the right-hand side of the...

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

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

Technique in which the polarization rotation of light, and its relationship to the magnetic field strength can be analyzed...

The greatest luminous reflectance possible for a specified chromaticity.

A nonoptical surface, within lenses and lens mounts, that contributes largely to flare by reflecting light into the image...

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

The distribution of one signal to more than one location. In a digital computer, it refers to the number of outputs that can...

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

The formation of a block by attaching optical elements to a plate with a ring of pitch or other thermoplastic material.

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

Formula used in convection study to express the ratio of buoyant force to viscous force.

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

Streaks of dense seeds with accompanying small bubbles.

Plastic optics refers to optical components or systems that are made from transparent plastic materials, as opposed to...

An image that can be studied three-dimensionally through a pair of complementary color filters composed of two superimposed...

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

Three-photon microscopy is an advanced imaging technique that belongs to the family of multi-photon microscopy methods. It...

The direct appreciation of the distance between a given object and the observer, or between the front and back of a solid...

In a mechanical system, any lost motion between driving and driven elements due to clearance between parts.

Thin-film deposition equipment refers to machinery and tools used in the process of depositing thin layers of material onto...

A design for bent crystal monochromators in which spacing is constant along any circular arc terminating at the two foci and...

The conversion of a still picture into sound waves and its subsequent transmission by radio.

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

A telescope with a concave paraboloidal objective mirror and a small plane (diagonal) mirror that reflects rays from the...

A dispersion-shifted fiber (DSF) refers to a type of optical fiber designed to minimize the effects of chromatic dispersion,...

A step before fusion splicing that involves cleaning the fiber end with low-current electricity.

A hyperspectral imaging camera is a sophisticated imaging device capable of capturing and processing data across a wide...

A primitive crystal possessing two plane surfaces that form a dihedral angle bisected by another plane surface.

Microscopic investigation of two-dimensional areas of a three-dimensional object that can be quantitatively evaluated by...

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

Flux per unit solid angle leaving a surface in any direction is proportional to the cosine of the angle between that...

The distance between pupil centers in a two-pupil system, measured perpendicularly to the optic axis.

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

A zone plate produced by a computer and having a binary structure that can be etched into a chromium or quartz layer. It...

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

Radiation emitted by electrons when they travel in circular orbits at speeds close to that of light. Synchrotron radiation...

In a lens, the square of the radius of its aperture divided by the product of the focal length and the wavelength. It...

A glass structure from which an optical fiber waveguide may be drawn.

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

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

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

Polarization refers to the orientation of oscillations in a transverse wave, such as light waves, radio waves, or other...

A controlled random search process, such as generalized simulated annealing, that has been incorporated into many optical...

A two-mirror corrector for a parabolic primary mirror that provides anastigmatic performance for large astronomical...

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

A cryogenic cooler device that is an intermittent Joule-Thomson refrigerator with a passive radiator serving as the...

1. The focal point. 2. To adjust the eyepiece or objective of a telescope so that the image is clearly seen by the observer....

A laser having a rare-earth chelate within a plastic host as the lasing material. The chelate laser is easily pumped and has...

A photometer used to measure sky brightness and polarization associated with zodiacal light, background starlight, F-region...

E.I. duPont's trade name for a material used in the jacket of fiber optic cables. It is flame-retardant, thermally stable...

A thermoplastic or thermosetting material used to hold an object fixed and keep it from deterioration. In microcircuitry,...

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

In a cathode-ray tube, the visible line or lines formed on the screen by the deflection of the electron stream.

An optical barcode reader, commonly known as a barcode scanner, is a device that uses optical technology to capture and...

The graphed curve illustrating the directional reflectance of a sample for different angles of collection.

A light valve that uses a crystal as the control layer medium and that operates on the principle of the electro-optic effect.

A theoretical, ideal lens capable of producing perfect images. Used as a lens design and analysis tool to image collimated...

Lenslike composition of stacked glass cylinders through which a spot of light appears as a streak perpendicular to the...

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

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

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

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

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

The use of computer analysis in the calculation of diffraction patterns for information on the design of optical systems. In...

The physical length of the light path in a substance divided by the refractive index of that substance. See also equivalent...

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

In image processing, the range of available gray levels. In an 8-bit system, the gray scale contains values from 0 to 255.

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

A simple form of astronomical telescope that uses a fixed objective and a focusable eyepiece. The objective forms an...

A light source that does not fluctuate despite temperature changes.

A system that is complete and self-contained, needing no further additions to permit its operation.

The observable illustration of an image, scene or data on a screen such as a console or cathode-ray tube, seen as a graph,...

In the SI system, prefix meaning 1 million, 106.

The naturally occurring crystalline form of silicon dioxide. It is slightly birefringent and exhibits rotary dispersion of...

A desklike apparatus with an opal glass surface illuminated from beneath by fluorescent tubes. It is equipped with roll...

A crystalline semiconductor material that transmits in the infrared.

That object distance at which a camera must be focused so that the far depth of field just extends to infinity. The near...

Conventional coordinates for optical system analysis, the X-axis being the horizontal, the Y-axis the vertical and the...

Spectrometric analysis of the distinct and characteristic spectra of atoms of elements. The atoms are energized to emit...

Calculations of lens aberrations whereby the first two terms of the series expansion are the only ones employed....

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

Made up of three components; for instance yttrium, aluminum and garnet (YAG).

An instrument designed to record the duration and intensity of solar radiation.

A chemical placed in a solution that will indicate when an excess of a substance or ion has been reached by coloring the...

An acid-resistant, lustrous volcanic glass, usually black or banded.

A fluorophore is a molecule or a portion of a molecule that has the ability to emit light upon excitation by an external...

A blank area (caused by insufficient inking of the paper) that falls within the range of an intended character stroke in an...

A halogen lamp, also known as a tungsten halogen, quartz-halogen, or quartz iodine lamp, is an incandescent lamp that uses a...

Also known as analog thermogram. The resultant photograph, illustrating, in tones ranging from black to white, the spatial...

Photodynamic inactivation (PDI) is a therapeutic approach that utilizes the combination of light, a photosensitizer, and...

A Laurent polarimeter is an instrument used in optics for measuring the rotation of plane-polarized light caused by...

A bundle of rays that originates from an object point on the optical axis of a lens system.

Any substance or space through which electromagnetic radiation can travel.

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

A silicon photodiode is a semiconductor device that converts light into an electrical current. It is a type of photodetector...

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

An SI prefix meaning one billionth (10-9). Nano can also be used to indicate the study of atoms, molecules and other...

1. Lines of the same color. 2. A term used in photoelastic stress analysis to refer to the interference fringes produced in...

An optically pumped solid-state laser in which the active medium is a neodymium ion in a glass rod host. Abbreviated...

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

The perpendicular orientation of the molecular axes of the nematic molecules in a nematic crystal, relative to the electrode...

With respect to a unit cell in a crystal structure, the property defining an atom located at the center of each face.

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

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

A device for inducing mode coupling in an optical fiber. Also, a device composed of one or more optical fibers in which...

A microscope to which a beamsplitter and illuminated reticle have been added to measure the radius of curvature of a...

The narrowest line of the cadmium spectrum; the red line has the purest radiation.

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

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

Gram-negative bacteria are a group of bacteria that possess a cell envelope composed of a thin layer of peptidoglycan...

The wavelength interval in which radiant intensity is at least 50 percent of the maximum spectral value.

A copolymer of styrene and acrylic used in molded optical components; it has a high refractive index and a low coefficient...

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

Also called scanning laser acoustic microscope. A device that uses high-frequency ultrasound waves to penetrate surfaces. A...

A low-power telescope with a wide field of view, typically attached to a higher power telescope with a narrower field of...

In a pumped laser system, the ratio of output energy to pump energy.

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

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

A closed-loop system that compensates for thermal blooming by optimizing only one parameter: the amplitude of the phase...

A type of quarter-wave retarder in the form of a glass rhomb; light entering the retarder undergoes two total internal...

A framework or latticework having an even arrangement of rods, or any other long narrow objects with interstices between...

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

Any of the photoelectric and thermal detectors, spectrographs and monochromators, thermographs, scanners, amplifier tubes,...

End-fire coupling refers to a method of coupling energy into or out of a waveguide, transmission line, or antenna, where the...

In an optical system, the gradual reduction of image illuminance as the off-axis angle increases, resulting from limitations...

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

A rear or front projection screen composed of minute optical surfaces that introduce a spread to the light beam that...

Metamaterials are artificial materials engineered to have properties not found in naturally occurring substances. These...

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

A band of light that appears along the outer edge of a transparent material under microscopic investigation and that moves...

Instrumentation designed to permit the perception, recording or measurement of scenes under conditions of low incident...

Qualitatively, the inverse of the amount of velocity produced by the application of a sinusoidal force to a system;...

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

A ray that has a nonisotropic speed in a doubly refracting crystal. It does not necessarily obey Snell's law upon refraction...

The equation devised by Sir G.B. Airy for the analysis of light diffraction near a caustic surface: (d2f/dz2) - zf = 0 where...

The apparent luminance of the image as seen through an optical system. This brightness of the image is determined by the...

An eyepiece located at the near end of the microscope tube. It often is a simple Huygens eyepiece, but compensating and...

The smallest linear diameter to which a laser or other beam of radiant energy is capable of being focused, depending on the...

A rapid change, as opposed to a long-term drift, of the emission wavelength of an optical source. Chirping is most often...

The splitting of an element's spectral line as the result of the interactions between the electron spin and the spins of...

The transparent fluid that fills the portion of the eye between the eye lens and the retina (the posterior chamber).

See crystal quartz; fused quartz.

Least value of color value combinations which gives white light; minimum purity as determined to be white.

A homogeneous solid solution with crystal lattice sites occupied, at random, by the molecules or ions of two or more...

An interference pattern that is recorded on a high-resolution plate, the two interfering beams formed by a coherent beam...

A salt of formic acid that can be used to enhance the photosensitivity of silver halide crystals.

Also known as HCS, an analytical method designed to collect statistically relevant amounts of quantitative data on many...

A camera tube that employs a high-velocity electron beam to scan a photoemissive mosaic and to store electrical charge...

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

A stroboscopelike apparatus that uses a copper vapor laser to illuminate an object for very short time periods (about 30 ns).

An evacuated, double-walled container for storing liquids at low temperatures. Often made of glass, the vessel resembles a...

A mirror whose coating serves to reflect visible radiation while transmitting the infrared.

Pyramid error in optics refers to an aberration in the shape of an optical surface, particularly in the context of mirrors....

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

A device that calibrates the size, position or distance of objects imaged on a video screen.

The ability of the human eye to adjust itself to an alteration in the intensity of light.

Micro-LED (micro-light-emitting diode) refers to a technology that involves the use of very small light-emitting diodes to...

The science of producing, recording, storing, transmitting and displaying visual images by any system (photographic, video,...

1. A device generally used in a cathode-ray or camera tube to emit a stream of electrons moving at uniform velocity in a...

An astronomical mirror, also known as a telescope mirror or primary mirror, is a key component of a reflecting telescope. It...

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

In semiconductor physics and materials science, the term "III-V materials" refers to compounds composed of elements from...

Synonym for multimode distortion. Also called mode dispersion.

A lensless photographic camera that uses a small sharp-edged hole as its aperture. The light passed by this aperture onto...

1. A term used to describe the clouded appearance of an incompletely polished surface that scatters light. 2. The...

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

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

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

The analysis of the properties of radiation, such as light, when acted upon by variations in the atmosphere. Blue and red...

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

A color whose hue is not produced by a single wavelength in the visible spectrum, but is instead produced by mixing the...

The movement of the eye as it focuses on details of a scene. Some imaging systems mimic this movement by small, rapid...

The growth of particular grain fragments in a metal or alloy, at the expense of others, that occurs when the metal or alloy...

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

Refers to transistors in which the working current flows through two types of semiconductor material: N- and P-type. In...

A blank whose basic surface curves are attained by heating and forming a given weight of raw glass; a rough glass blank...

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

The Mills Cross telescope is a two dimensional radio telescope in which the two antenna arrays are positioned perpendicular...

A caustic formed by reflection.

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

Distortion of an optical component as a result of heat, which can influence the divergence and the mode quality of a beam...

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

A five-sided prism containing two reflecting surfaces at 45° to each other, and two refracting faces perpendicular to...

A scanning electron microscope (SEM) is a powerful imaging instrument used in scientific research, materials...

The negative distortion that causes a square grid pattern to be imaged as barrel-shaped.

A solid-state semiconducting structure (basically one of the bolometers) that changes electrical resistance with...

A lens aberration, resulting from different magnifications in the various lens zones, that occurs in that part of the image...

A process by which a plastic cell is molded around a glass lens or lenses to create a mount, eliminating the metal barrel...

The study of visual perception by the sense of sight.

In an optical system, the space between the object being viewed and the system entrance pupil.

Basically, a hydrogen atom with two alterations, positronium is the lightest atom in the universe and has an extremely light...

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

Distortion caused by variations in the rate of change of phase shift with frequency over the signal's necessary bandwidth.

A YAG crystal refers to a solid-state crystal made of yttrium aluminum garnet (YAG), which is a synthetic crystalline...

A feature of some imaging devices, such as digital cameras, that allows them to compensate for different lighting conditions...

The distortion created because the different frequencies of a signal have different propagation velocities through a medium.

Line scan refers to a method of capturing images or data by scanning a single line at a time, as opposed to capturing the...

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

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

A scientific CMOS (complementary metal-oxide-semiconductor) camera is a type of digital camera specifically designed for...

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

In optics, the term image jump refers to a displacement or shift in the apparent position of an image when a change occurs...

A cylindrical convex viewing mirror used for viewing distorted pictures formed by photographing the reflections of the...

An optical instrument designed to permit the visual examination of the interior of the bronchi.

A visual, single-unit spectrophotometer with a biprism and a Wollaston prism. The Wollaston prism polarizes coincident...

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

An x-ray or radium photograph illustrating the nonuniform density of the structure that the rays penetrate.

The separation between the exit pupils of a binocular instrument. This usually is adjustable so that it can be set equal to...

A television system in which the images produced appear three-dimensional.

A microscope that can be used to observe and magnify microscope specimens while they are being centrifuged. The objective...

The state of a carrier signal that corresponds to maximum picture brightness in a television system.

Although low in sensitivity (approximately 10-7 m for helium-neon lasers), this holographic technique permits quantitative...

The study and utilization of interference phenomena, based on the wave properties of light.

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

A system of beacons used in navigation.

A prefix that is used to represent 109 or 1,000,000,000 in the SI system.

A prism produced by severing a Nicol prism and reconstructing the polarization angles of the two halves so that they are...

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

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

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

A system of modular mechanical components for building precision optical systems. The basic equipment includes a variety of...

A caustic formed by refraction.

The near-point distance of the normal eye. The value of 10 in. or 25 cm is normal. This value is used in evaluating the...

A disc composed of a series of holographic optical elements that diffract light at various angles. When spinning, a raster...

A method of producing high-quality plastic optics in large volumes by injecting the heated, liquified plastic at high...

A form of liquid crystal widely used in displays, achieved by sandwiching a liquid crystal material between two substrates...

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

A reference sphere used to represent all possible states of polarization. All linear polarizations will lie on the equator...

A wireless stereo imaging device used in conjunction with a monitor to produce a virtual interactive environment. Liquid...

A transparent sphere that has an index of refraction that is different from that of the medium surrounding it; used in...

The term half bandwidth (HBW) generally refers to the width of a spectral band or frequency range at half of its maximum...

A type of computer in which the electronic circuits, which process data serially, are replaced by photonic circuits capable...

The greatest luminous transmittance possible for a specified chromaticity.

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

A dome-shaped structure used for some optical instruments in place of a flat window. The transparent material should be of...

An instrument that contains a spectrograph with a grating in which an array of slits, in place of a photographic plate, is...

The study of the arrangement of atoms in a crystal by means of x-rays.

Spatially offset Raman spectroscopy (SORS) is a technique that extends traditional Raman spectroscopy by incorporating...

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

A chart on paper or glass containing a series of sets of lines at progressively smaller spacing and used to ascertain the...

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

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

Germanium crystal refers to a crystalline form of the element germanium (Ge), which is a metalloid and semiconductor...

Glass designed to absorb most infrared and ultraviolet radiation while transmitting most of the visible region.

The Kerr effect, named after the physicist John Kerr who first observed it in 1875, is a nonlinear optical phenomenon where...

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

A system used to measure very small displacement by electrical means.

A laser that sends data from the source to the distribution node.

A Fresnel lens is a type of optical lens that consists of a series of concentric grooves or steps carved into a flat, thin...

A piece of glass, pyrex or quartz having one or both surfaces carefully ground and polished plano, generally flat to less...

A beam instability, induced by index of refraction inhomogeneities and component damage of dirt and dust particles, that...

The letter form used on visual performance test charts. The overall letter height is equal to five times the thickness of...

Scalar diffraction theory is a simplified approach used to describe the propagation of electromagnetic waves, particularly...

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

An eyepiece consisting of a planoconvex field lens and a cemented doublet as the eye lens.

In a general sense, any one of a class of instruments used to disperse radiation, visible or invisible, into its component...

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

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

A device that samples and quantizes a signal in digital form for storage in memory.

An instrument used to test the hardness of various materials. It measures the pressure on a standard point that is necessary...

A furnace, generally electrically heated, with a control system capable of following a cam by which the temperature can be...

A well controlled thin films technique for growing films with good crystal structure in ultra high vacuum environments at...

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

Type of solid-state display tube in which the readout surface is coated with a material that changes color when positively...

A plane along which destructive interference takes place.

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

A container designed to hold recording material (film, video- and audiotape) so that when it is loaded into a recording...

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

An imaging technique used in radiology that is based on the principles of nuclear magnetic resonance (NMR) to produce...

1. The use of an electronic microdensitometer to measure points of equal density on a photographic deposit. 2. A technique...

A telescopic system having an eyepiece, a reticle and an objective. The instrument measures wavefront power in diopters.

A viewer that uses the transmittance of polarized light through glass or a similar medium to examine strained regions. See...

The lens located at the object end of a microscope tube. A wide range of objectives is available, including simple...

A fluorescent screen refers to a phosphorescent or fluorescent-coated surface that emits visible light when exposed to other...

The spectroscopic study of radiation emitted by the process of fluorescence.

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...

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

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

Spectroscopy used to study the concentration, diffusion and Brownian motion of small particles suspended in a fluid by...

A projection screen having vertical ribs or flutes set into a plastic surface.

Standard light source representative of the quality of specified natural or artificial illumination.

High dynamic range (HDR) refers to a technology that allows for a broader and more dynamic range of luminosity in visual...

An enclosure whose walls are coated to absorb completely all radiation striking them.

In the optical field, a tube to which a lens is fastened for centering.

A sound wave that travels through a piezoelectric material.

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

Supercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the...

A system of Japanese origin that utilizes Fresnel lenses and a fiber optic network to transmit sunlight to otherwise...

A device that provides means for accurately moving minuscule tools over the surface of a microscopic object. The motion...

An acoustic wave that propagates along the surface of a solid and decays exponentially with substrate depth. Also called a...

Second-harmonic generation (SHG) is a nonlinear optical process that occurs when two photons with the same frequency combine...

For an electromagnetic field mode varying sinusoidally with time at a given frequency, the logarithmic rate of change, with...

Discipline within optical physics that addresses sound vibration, phonon effects and their influencing behavior within...

An instrument used to record sound, pictures or both on a magnetic tape for storage and playback.

Measurement of absorption by the gas of interest in the 2- to 6-µm range as a function of tangent height pressure. The...

An intensity distribution (intensity as a function of radial distance from the beam center) which is given by the Gaussian...

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

The study of radioactive substances and high-energy radiations such as x-rays and g-rays.

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

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

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

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

The surface of an optical fiber that is used as a reference when joining optical fibers. Although the outermost cladding is...

A system for automatic industrial process control or measurement, consisting of an optical module for image acquisition, a...

The adhesion of two sufficiently clean and close-fitting surfaces without the use of cement or glue. The optically contacted...

A spectrum having some lines that are darker than others or that contrast against a light, continuous-spectrum background.

In micropositioning systems, motion (most frequently undesired) about the Z-axis.

1. A generic term for detector. 2. A complete optical/mechanical/electronic system that contains some form of radiation...

A lens that is symmetrical and designed to work between 1:1 and about 4:1. It covers a field of about ±20° at f/8...

A resampling and interpolation method that uses only the value of the nearest neighbor pixel, while not considering values...

The second adjustable iris diaphragm in an optical system. In the common microscope condenser system, it usually is located...

In the SI system, prefix meaning one hundredth, 10-2.

An optical scanning system found in most computer scanners that can read documents, often in many type styles, and convert...

An aberration that remains after primary color is corrected. Primary color causes the back focus of a lens to vary with...

An afocal optical device made up of lenses or mirrors, usually with a magnification greater than unity, that renders distant...

The study of the reflection or transmission properties of specimens as a function of wavelength after they have been excited...

1. A single unit in a device for changing radiant energy to electrical energy or for controlling current flow in a circuit....

A telephoto lens form noted for its lack of distortion.

The ongoing expansion of the universe based on observations of the recession of distant galaxies from each other as...

A neutral-colored gelatin wedge, cast between glass plates, that is used as an intensity scale in certain types of...

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

In the SI system, prefix meaning one-millionth, 10-6. Abbreviated µ.

A filter that transmits light in a series of sharp, widely spaced wavelength bands by its sandwich construction of...

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

A term that describes any state of glass before its manufacture as an element.

A system in which a supplied signal causes the deflection of the electron beam in a cathode-ray tube, thus forming a visible...

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

A mechanical device designed to smoothly vary the effective diameter of a lens, thereby controlling the amount of light...

The bending of x-rays by the regular layers of molecules in a crystal acting like a very small diffraction grating. The...

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

A common form of high-precision, ceramic-based actuator capable of moving and measuring at the nanometer level.

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

A Kerr soliton refers to a specific type of soliton, a self-reinforcing wave packet, that arises in nonlinear optical...

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

A Bose-Einstein condensate (BEC) is a state of matter that forms at temperatures close to absolute zero. It is named after...

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

The analysis of the atomic structures within crystals by means of x-ray diffraction.

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

Radiation in which the phase relationship between any two points in the radiation field has a constant difference, or is...

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

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

A system that applies a crystal as a diffracting agent to photograph the spectrum.

A camera tube widely used in television broadcasting. It consists of three sections within a single vacuum envelope. 1. A...

Also called calcite. A natural hexagonal crystal of calcium carbonate. It cleaves readily into rhomboids useful in the study...

A prism or prism assembly that serves to displace the instrument's optical axis.

A medical imaging device that uses a ring of crystal/photomultiplier tube assemblies encircling the patient to detect gamma...

A lamp whose output can be traced to a standard light source.

A contour mapping technique that uses electronic scanning and sampling techniques instead of a reference grating (see moire...

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

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

The process of determining, with the aid of plane-polarized light, the stress distribution in materials under complex...

The wavelength at which a lamp radiates its highest intensity.

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

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

A type of sheathing for fiber optic cable that incorporates a coil of metal; often used in harsh environments.

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

A device that permits only electrons within a narrow velocity range to pass through it, while rejecting those above and...

Also known as zonal axis. The axis positioned through the center of a crystal that is parallel to a zone edge.

Elastic deformation of a dielectric caused by volume force when the dielectric is placed in an inhomogeneous electric field.

The frequency domain is a concept used in signal processing and analysis to represent signals and data in terms of their...

An electron instrument used to reflect an electron beam totally.

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

A spectrograph in which the refracted beam returns almost along the path traveled by the incident beam, and is brought to a...

See eye test apparatus; ophthalmic instruments.

The term applied to the geometrical structure of radiometry or of the propagation of any quantity that is conversed and that...

A receiver for optical communications systems consisting of a symmetric binary, pulse-code-modulated transmitter, a...

The efficiency of scattering by an atom in a particular direction, expressed as: where AA is the amplitude of the wave from...

The arrangement of two Porro prisms so that the inverted image formed by certain types of optical instruments is the same as...

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

The use of a small ultrastable master oscillator (a diode-pumped Nd:YAG laser) to achieve single-frequency operation of a...

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

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

The use of a tightly focused beam of electrons to drill minute holes in substances. The drilling is accomplished by the...

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

The successive analysis or synthesizing of the light values or other similar characteristics of the components of a picture...

A hologram formed without lenses and with the object and reference points sharing the same plane. In the initial recording,...

Also known as integrated exposure. A measurement of light from sources that vary rapidly with time, defined as the integral...

The portion of a reproduced image having the greatest luminance.

The angular spectrum approach is a mathematical and computational technique used in the field of optics to analyze and...

Horizontal concentrations that comprise the dominant factor in atmospheric gradient correction. The range bias near due...

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

The analysis of metal structure using an optical or electron microscope, generally with a camera, to record observations.

In passive optical components, loss that varies as the polarization state of the propagating wave changes. Expressed as the...

A linear image sensor is a type of solid-state electronic device used to capture and convert light into electrical signals....

The photographic recording of the heat radiation emitted from various points on the object as corresponding density...

Observed electroluminescence of zinc sulfide phosphors when excited by an electric field. This effect is the basis for the...

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

After putting a thick photographic emulsion on a front-faced mirror, and exposing the emulsion to monochromatic incident...

A vacuum pump in which heated oil or another substance is forced through jets as a vapor that collides with gas molecules...

The adjustment of a binocular instrument so that the lines of sight of both telescopes are parallel.

A device used in ultrasonic imaging to measure the velocity and attenuation of compressional waves in a transparent liquid...

The optical form of the crystal fluorspar, calcium fluoride, that is utilized for its low optical dispersion, its low...

1. A thin parallel plate of material that transmits in the infrared region. See infrared optical material. 2. A spectral...

Low-insertion-loss fiber coupler fabricated from a sheet of light-sensitive material laminated onto a fused quartz substrate...

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

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

The intermolecular attraction between two surfaces, as between a substrate and a coating; it is an important factor in the...

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

Spectrum broadening that results from the influence of an electric field.

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

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

In image processing, a specially designed programmable computer peripheral that attaches to the host system for the purpose...

Radiation emitted from vibrating charged particles. A combination of oscillating electrical and magnetic fields that...

An electron tube that stores and visually displays information by means of a cathode-ray-beam-scanning and charge-storage...

A Nernst glower, also known simply as a Nernst lamp or Nernst filament, is a type of incandescent lamp or radiant heater...

A light source that emits an uneven distribution of radiant energy through the visible range.

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

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

Videography refers to the process of capturing moving images and recording them in a digital format. It involves the use of...

The desensitization of the first photographic exposure after it has been subjected to high-intensity radiation.

An optical system having one or more lens or mirror components that have nonspherical surfaces. These surfaces, whether...

A magnetometer is a scientific instrument used to measure the strength and/or direction of a magnetic field. It can detect...

In the SI system, prefix meaning 1018. (E).

A refracting telescope that uses a prism to bend the line of sight 90°.

Any irregular motion, variation in intensity or change in color that arises because of atmospheric turbulence during the...

Spectroscopy is a technique used in the study of interactions between matter and electromagnetic radiation. It involves...

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

In computer graphics, the point on the display screen where the electron beam is located before the display instruction is...

The placement of a device or an additional circuit into a feedback control system to improve its response in relation to a...

An instrument consisting of a high-voltage vacuum tube used to form hard x-rays or high-speed ion beams. By partitioning the...

Diamond turning refers to a precision machining process used to produce complex optical components, particularly lenses and...

The greatest wavelength of radiation for a specified surface for the emission of electrons.

A breakout cable, also known as a fan-out cable or breakout assembly, is a type of cable that combines multiple individual...

In physics, nuclear fusion refers to the process in which two atomic nuclei come together to form a heavier nucleus,...

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

One of the four functions that allows the computation of a transparent medium's index of refraction, provided the index has...

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

A type of stereoscopic photography in which a pair of lenses focuses a pair of images, relative to the positions of the two...

The least angle of incidence at which total internal reflection takes place. The angle of incidence in a denser medium, at...

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

The fine scratches formed when, in hand centering, the forked stick used to move the lens on the chuck marks the rotating...

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

The modification of the spherical surfaces in an optical system to correct for spherical aberration.

A physical source of radiation, as contrasted to illuminant. See illuminant.

LiFi, short for light fidelity, is a wireless communication technology that utilizes visible light or infrared light to...

Optical glass refers to a type of glass specifically engineered and manufactured for use in optical components and systems,...

Embedded vision refers to the integration of computer vision technologies into various embedded systems, devices, or...

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

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

A soft, malleable, stable rare-earth element. Holmium laser systems are used in surgical procedures involving the cutting...

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

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

Quantitative phase imaging (QPI) is an advanced imaging technique used in microscopy to measure and analyze the optical...

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

A parallel plate of glass in such a position that the refracted and reflected rays of incident parallel light are mutually...

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

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

With respect to display systems, a device that uses an independent light source and a control-layer medium, the active...

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

The vertical or horizontal distance between two addressable points on a display screen; indicates the basic resolution...

An imperfection in optical glass consisting of a distinct streak of transparent material having a slightly different...

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

An instrument with a fluid that modulates a light beam traversing it because of the effect of ultrasonic waves passing...

1. A strainmeter capable of measuring the change in the relationship between two reference points, provided that the points...

An aperture consisting of a semitransparent central region whose amplitude transmittance only is varied, and the relative...

Intensity distribution in the image of an edge. The gradient of the edge-response curve is a measure of the image quality of...

The manifestation of light from scatterers outside the plane of the object in coherent light systems. The output of these...

Spherical or chromatic aberration in a lens having a wide aperture. It is present because the refracting power varies for...

A mold for glass or plastics often made of stainless steel to prevent pitting or oxidation in service. It is polished to the...

A photoconductor that demonstrates increased conductivity during its exposure to infrared radiation.

A spectrum that displays the distribution in mass or in mass-to-charge ratio of ionized atoms, molecules or molecular parts....

A device that measures the spatial distribution of energy perpendicular to the propagation path of a radiant beam. An energy...

A swept-source laser, also known as a wavelength-swept laser, is a type of laser that rapidly and continuously changes its...

Fixed-pattern noise is the measure of the static (nontemporal) differences between pixels when the detector is evenly...

The splitting or shifting of spectral lines or energy levels caused by the application of a strong transverse electrical...

In the SI system, prefix meaning 10-18.

An ocular having two planoconvex lenses that are formed from similar glass and that are separated by a space equal to half...

Refers to the characteristic hue of the ocean according to the presence and concentration of specific minerals or...

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

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

A type of glass used in telescope mirrors, formed by adding a nucleating agent to standard glass and then heating it until...

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

Aspect of vision permitting the observer to distinguish among stimuli by their hue, saturation, and brightness or lightness.

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

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

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

Optimization method used in optical design computer programs that employs a variable-by-variable approach to construct new...

A thin, stretched plastic membrane cemented to a rigid supporting ring. It may be coated to act as a beamsplitter, for...

An opaque shielding device designed to reduce the effect of stray light on an optical system.

A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates...

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

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

The pressure or stress of one newton per square meter.

The term gradient-index profile refers to a specific type of refractive index distribution within an optical material. In...

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

The amount by which an optical surface deviates from its ideal design value, expressed in wavelengths of light. Optical...

Descriptive of an optical fiber having a core refractive index that decreases almost parabolically and radially outward...

A stimulus that contains equal energy at each wavelength in the visible region of the spectrum.

A means of illumination from which the infrared component has been removed by absorption or reflection filters within the...

A small half-shade analyzer placed in the eyepiece of a polarimeter to determine the character of the polarized light...

Extreme ultraviolet (EUV) refers to a specific range of electromagnetic radiation in the ultraviolet part of the spectrum....

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

A transistor that uses an electro-luminescent source, a transparent base and a photoelectric collector.

The transition cross section constant coefficient which defines the transition probability of absorption from ground to a...

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

A liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the...

Deep ultraviolet (DUV or deep-UV) refers to a specific range of ultraviolet light with shorter wavelengths than those in the...

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

A holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists...

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

Frequently used in astronomical measurement, it is based on the diurnal rotation of a star relative to the fixed stellar...

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

A strong, heat-resistant glass that contains a minimum of 5 percent boric oxide.

A technique for depositing a material coating on metal, ceramic, semiconductor or polymer substrates. The interaction of...

With respect to the crystal, the decrease in energy that follows the process whereby the ions, separated from each other by...

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

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

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

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

Die bonding is a critical process in semiconductor manufacturing and microelectronics assembly, where a semiconductor die or...

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

A television display system in which the television signal is converted to an image that is projected onto either a front or...

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

A system of sensors and related instrumentation that allows a navigable object (usually a missile) to locate its destination...

A small mass spectrometer used to find leaks in a vacuum system by detecting the presence of helium. Using a magnetic...

A system that generally uses a photodetector to decode punched cards for information, or for input to a computer, by sensing...

1. In the geometric sense, an abbreviation for the term "sagitta,'' the height of a curve measured from the chord. ...

A photofluorescent compound that, when used with a scintillating substance, absorbs photons and emits related photons having...

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

Systeme Internationale d'Unites, the international metric system of units.

A method of producing an essentially constant output signal from an electronic circuit despite variations in the strength of...

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

Piezoelectric transducers are devices that utilize the piezoelectric effect to convert electrical energy into mechanical...

An optical system of variable focal length, the focal plane remaining in a fixed position. This result is achieved by moving...

Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In...

A type of copying camera in which the object is placed on a horizontal easel and photographed by a horizontal camera above...

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

A direct method of measuring refractive index that works best with flat-surfaced samples (i.e., those that are not dependent...

Radiographic recording and enhancement of the micoscopic details within the structure of thin specimens at a high...

In optics, a motion controller refers to a device or system that precisely controls the movement of optical components, such...

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

An instrument in which an image of the sun is scanned by the entrance slit of a monochromator, the exit slit simultaneously...

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

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

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

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

Eye blink or head movement in response to bright light. Aversion responses such as blinking are sufficient protection from...

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

A long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or...

Surface-enhanced Raman spectroscopy (SERS) is an analytical technique that combines the principles of Raman spectroscopy...

An InGaAs (indium gallium arsenide) camera is a type of imaging device that utilizes InGaAs sensors to capture images in the...

A semitransparent mirror in an optical system that combines two or more output beams into a single coaxial beam.

In ophthalmic practice, an instrument that determines the boundaries of the field of view. It is composed of a 2-m square of...

The natural log of the ratio of absorbed intensity over the total intensity which gives a constant value assuming a stable...

Plasmon ion-assisted deposition (PIAD) is a technique used in thin-film deposition processes, particularly in the production...

Abbreviated SoC. A single chip containing all the electronic circuits required for a complete, working product. SoCs are...

The three lines in the spectrum of cadmium that have the purest radiations and that were first used by Michelson to...

Laser sintering is an additive manufacturing (AM) or 3D printing technology that involves using a laser to selectively fuse...

A laser or laser system positioned within an enclosure to prevent dangerous optical radiation from leaving the enclosure.

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

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

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

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

A spectroscopic technique that combines the high chemical specificity of Raman scattering and signal sensitivity provided by...

A false image in television that follows the desired image so closely that it appears to be smeared.

The signal-to-noise ratio (SNR) obtained with a Fourier transform spectrometer when detector noise prevails, which exceeds...

A technique for producing micron-size structures on surfaces by using short-wavelength light or electron beams.

The shape of the edge of a concave surface when the depth of the bevel plane to the vertex of the surface is controlled to a...

A cascade amplifier that uses a common cathode resistor to couple energy from stage to stage.

Electron lens consisting of an homogeneous axial electric field.

An interferometric method for describing the surface shape of large coated or uncoated optical flats. The procedure uses a...

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

Capacity of a vision system to capture an image of an object in motion and to resolve the direction and speed of that motion.

1. The reduction in the developable density of a photographic emulsion that has been extremely overexposed. 2. In a laser...

The simplest, most inexpensive type of camera, which is shaped as an oblong or square box, containing the simplest lens,...

An absorbing coating medium between fibers, used in some fused fiber optic plates to absorb unwanted light. Such coatings...

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

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

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

The distortion of an object's true image as the result of abnormal atmospheric disturbances along the path traveled by the...

The measurement of the ability of matter to absorb, transmit or reflect infrared radiation and the relating of the resultant...

Also referred to as a funduscope, an ophthalmoscope is a specialized instrument used by ophthalmologists for observing and...

The alignment process that makes the optical axes of two related systems parallel to each other. Also, making the optical...

An instrument that uses a photoelectric system to determine the size and volume of dust particles in a given unit of air.

Etaloning is an optical phenomenon that occurs in imaging systems, particularly in devices such as spectrometers,...

A change in the refractive index of an optical fiber caused by variation in the length of the fiber core in response to...

Oscillation in rod and disc amplifiers that critically limits the achievable energy storage.

A charge-injection device (CID) refers to a class of devices that manipulate and detect electrical charge within a...

A measure of the relative difference in refractive index between two optical materials. Most commonly used in fiber optics...

An instrument providing a continuous measure of color.

Relative to a light source, the frequency at which the source appears to fluctuate in light intensity half the time and...

In a fiber optic cable, the longitudinal length required for the transmission media, wrapped around a central member, to...

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

1. The process of following an object's movement; accomplished by focusing a radar beam on the reticle of an optical system...

In astronomy, the method of deliberately viewing objects with peripheral vision to take advantage of the eye's greater...

A telescopic light-sensing meter used to measure illumination levels of small regions at a distance of many feet; it is used...

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

The apparent color, as seen by the human eye, as distinguished from color as a measurable property of light.

A filter designed to improve contrast in an imaging system. For visual and black and white photosystems, a yellow filter is...

Near-infrared spectroscopy (NIRS) is a non-invasive analytical technique that uses the near-infrared region of the...

Operation in which the dispersion of a pulse limits the distance between repeaters in optical systems. Waveguide and...

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

STED microscopy, or stimulated emission depletion microscopy, is a superresolution imaging technique in fluorescence...

A device that serves to emit light of the same wavelength as the input light, only with an increase in intensity. It may be...

Reflectance spectroscopy is a technique used to analyze the reflective properties of materials across various wavelengths of...

Instantaneous field of view (iFOV) is a term commonly used in the context of remote sensing, imaging systems, and optical...

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

1. The characteristic of how light propagates through a waveguide that can be designated by a radiation pattern in a plane...

The distance between the locating surface of the lens mount and the image plane.

Liquid crystals are a state of matter that exhibits properties intermediate between those of conventional liquids and solid...

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

1. In glass, a solid inclusion having a small diameter. 2. A particular, single crystal that, after undergoing the...

The determination of axially symmetric and asymmetric refractive-index distributions by use of interferometry carried out on...

Immunohistochemistry (IHC) is a method for detecting antigens or haptens in cells of a tissue section by using labeled...

A camera accurately aligned to a weapons system to provide a photographic record of system performance.

The number of molecules in one gram mole of a substance, numerically approximated by 6.02 x 1023.

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

A representation of the shape of a surface, including any roughness or other irregularities. The profile can be generated by...

The continuous group of waves that persists for a short time only.

A state in which an image is distorted by an optical system.

A three-terminal semiconductor having only one PN junction and a stable, open-circuit, negative-resistance property.

A system mounted a few inches above a moving plane that consists of a light source, lenses and one or more phototubes. In...

An opaque inclusion in glass that contains undissolved or crystalline material. Also known as a seed.

Light striking a surface at an angle almost perpendicular to the normal.

Fused quartz and silica are closely related materials, both composed primarily of silicon dioxide (SiO2), but they are...

A whole-flow-field technique providing instantaneous velocity vector measurements in a cross-section of a flow that is...

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

An optical instrument, generally a polarizing microscope, that is used to determine the interference figures and optical...

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

An image intensifier, also known as an image intensification tube or image intensification device, is a specialized...

An adhesive whose viscosity decreases as the temperature is increased to a limit. Canada balsam, resin and pitch are...

A Michelson-type interference microscope used to produce interference patterns of reflective specimens through the...

Any material of a macromolecular nature that can stretch at room temperature to more than twice its length and return to...

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

The smallest amount of photon energy to pass a detector window and be counted.

A lens with aberrations corrected to the point that residual wavefront errors are substantially less than one-quarter the...

A calcium indicator is a molecule that is sensitive to changes in calcium ion (Ca2+) concentrations in biological systems....

That point in the electromagnetic spectrum at which an optical system focuses the most chemically effective rays.

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

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

A photograph reduced to the microscopic scale and stored on a microfilm as seen with microfiches for the purpose of storing...

The use of an applied electrical field to focus a cathode-ray tube's electron beam.

An instrument used to record infrared images of large areas. The recorded data are used to produce maps in false color...

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

A common aberration in lenses covering large fields of view; it results in images of objects near the edge of the field...

In image processing, the memory that stores the values for the point processes. Input pixel values are those for the...

An instrument that can preselect intervals, often in increments of 1, 10 or 100 ns, for the generation of electronic pulses...

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

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

An electronic display in which a flat screen is formed by an orthogonal array of display devices, such as electroluminescent...

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...

An acousto-optic modulator (AOM) is a device that utilizes the interaction between sound waves and light waves to modulate...

A statistical analysis of facts obtained when the intensity of x-ray diffraction is calculated at different angles. In this...

The average length in a specific material in which a relativistic charged particle will lose 67 percent of its energy by...

Temperature of the blackbody having chromaticity nearest to that of the test source on a specified chromaticity diagram.

The resistance of individual grains of an abrasive to breaking down under pressure. If the grains break down under...

A pixel, short for "picture element," is the smallest controllable element of a digital image or display. It is a...

Simulation of atmospheric turbulence for laboratory experimentation purposes, achieved by creating an unstable vertical...

Any pyrheliometer that has a filter placed over its sensor to limit the range of solar radiation it will detect; used to...

The material that produces stimulated emission from within a laser oscillator. Laser gain media may vary from...

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

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

A method of fabricating an optical waveguide by melting the core and clad glasses in two suitably joined concentric...

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

A package for an optical fiber or fibers that may include cladding, buffering, strength members and an outer jacket.

A method used in facsimile scanning that sweeps the elemental area across the copy in a spiral motion as the result of the...

An exciton is a quasiparticle that represents the bound state of an electron and a hole in a solid-state material, typically...

An amorphous film in which cylindrical bubbles of reverse magnetization can be formed to follow circuit paths usually made...

A microdensitometer that contains a scanning stage to provide simultaneous representations of position vs. density.

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

A mode in an optical waveguide whose fields are transversely oscillatory everywhere external to the waveguide. It exists...

A measure of the ability of a photographic system to record fine detail. Usually stated in terms of cycles per millimeter on...

The radiant energy emitted within a time period per unit solid angle, usually measured in watts per steradian.

The region of the cathode-ray tube phosphor screen restricted by the tube and instrument specification.

1. A stereoscope that has adjustable scales to allow the determination of distances and dimensions from stereoscopic...

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

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

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

A detector-Dewar assembly typically refers to a combination of a detector and a Dewar flask used in scientific instruments,...

A vision defect commonly referred to as nearsightedness. The defective condition results when the image of a distant object...

A technique used in integrated optics where a groove is cut on a substrate surface and covered by a thin film to facilitate...

In an optical waveguide, that dispersion attributable to the variation of refractive index profile with wavelength. The...

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

A bulk crystalline optic which permits the propagation of light through a volume of index altered material. The variation in...

A device incorporating a spatial light modulator and a reference filter; used for matching an input optical waveform or...

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

1. A method of photographing distant objects with a lens of long focal length. 2. The reproduction of photographs over a...

Photobleaching is a phenomenon in which the fluorescence of a fluorophore (a fluorescent molecule or dye) is permanently...

Turbidity is a measure of the cloudiness or haziness of a fluid caused by the presence of suspended particles. These...

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

A photon jet is a narrow, highly collimated beam of light that is formed when light interacts with small dielectric...

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

imaging system which clearly shows the IR signals in the field of view as well as ambient environment

Stress applied to an optical fiber at a constant rate.

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

1. The anode or anticathode of an x-ray tube that emits x-rays when bombarded by electrons. 2. The screen in a television...

A structure consisting of a thin film of liquid crystal sandwiched between light-polarizing filters that have received a...

Light leakage at a total reflecting interface when another highly refractive medium is brought close to it.

The strongest light emitted by the Earth's upper atmosphere. It most often can be viewed in the Arctic as the aurora...

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

A laser resonator in which a mode oscillating between the mirrors will converge upon the laser's longitudinal axis.

Förster resonance energy transfer (FRET) is a mechanism describing the transfer of energy between two closely spaced...

A specified cold-cathode gas tube used to apply a short-duration, high-power arc for a stroboscope.

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

In rangefinders and height finders, a rotatable or sliding wedge-shaped element used to divert the line of sight precisely...

Any of the five elements astatine, chlorine, fluorine, bromine and iodine, grouped because their chemical properties are...

Electromagnetic radiation that is emitted by an electron as it is accelerated or decelerated while moving through the...

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

An LED (light-emitting diode) is a semiconductor device that emits light when an electric current passes through it. LEDs...

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

Plates of glass containing as many heavy metal oxides as can be dissolved in the glass without causing devitrification. The...

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

Fizeau fringes are interference fringes observed in an interferometer, specifically in a Fizeau interferometer. The Fizeau...

A solid with a structure that exhibits a basically symmetrical and geometrical arrangement. A crystal may already possess...

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

An optical time-domain reflectometer (OTDR) is a specialized instrument used in optical fiber communications to characterize...

A mount that uses a floating suspension and a motor-driven gyroscope to keep a motion picture or still camera at a set angle...

An imaging process, similar to specific Doppler mapping radar techniques, that utilizes a laser, an optical imaging system,...

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

An electronic device used to encode video and audio signals of a television camera into radio waves that are broadcast to...

An instrument used to determine the absolute or relative scatter levels of optical surfaces.

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

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

In image processing, the study of structure or form of objects in an image.

A fluorographic method whereby the sensitive photographic medium is pressed against a fluorescent screen to form a visible...

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

In computerized industrial process control, the element that determines the choice and sequence of operations dependent on...

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

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

A system consisting of two or more Geiger-Müller counters, connected in coincidence with their centers on an axis. The only...

Referred to as SWCNTs, these cylindrical nanostructures composed of a folded sheet of graphene can be used as near-infrared...

The mean square difference in refractive index for two separate points in space.

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

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

Process of analysis in which the analyte substance is distributed in a matrix before laser desorption. This method avoids...

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

The calculated normal distance from a photon source at which harmful interaction with the incident light will occur....

Sapphire optical fiber is a type of optical fiber made from single-crystal sapphire, which is a form of aluminum oxide...

Particle acceleration refers to the process by which charged particles, such as electrons or protons, gain kinetic energy...

A form of a stereoscopic microscope having paired objectives, prisms and eyepieces, and invented by H. Greenough.

A type of eyepiece, or the modification of an eyepiece, in which a small hole, without a lens, functions as the eye lens;...

A solid-state device similar to an ordinary transistor except that incident light on the PN junctions regulates the response...

The limited light-gathering area of an optical system. The area is normally restricted to an edge or outer surface of an...

Glass that has been specially treated so that it will not shatter when exposed to high temperatures followed by immediate...

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

The quality of asymmetrical intensity distribution in a laser beam, as opposed to a circular distribution.

An astronomical telescope is a type of optical instrument designed to gather and magnify light from distant celestial...

In image processing, any operation that strengthens information about the edges of objects displayed. Three types of spatial...

The Golgi staining technique (also called the black reaction) makes it possible to look at the nervous system by rendering...

An X-Y electrically addressable series of arrays with individual electron emitters bombarding a phosphor-coated transparent...

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

Laser surgery refers to a medical procedure in which a laser, or focused beam of light, is used as a precision tool to cut,...

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

A holographic plate coated by photopolymeric mixtures that are composed of one or more monomers and a photoredox catalyst...

An optical diffuser is an optical component or material designed to scatter or diffuse light that passes through it. It is...

An optical grating, in the context of optics and physics, refers to a device with a periodic structure of closely spaced,...

The maintenance of the same scanning relationship between the transmitting scanning spot and receiving scanning spot for...

A thermoplastic, self-extinguishing polymer with excellent high-temperature, low-creep and arc resistance properties.

A device that completely or partially restricts the amount of light reaching the eye.

A phage, short for bacteriophage, is a type of virus that infects and replicates within bacteria. Phages are composed of...

Total number of characters available to each position of a digital numeric system.

A source that attempts to create the characteristics of an ideal blackbody. It consists of a cavity, generally spherical,...

A system that uses the heat from a pulsed laser to weld metals. Because of the rapidity and localization in which the...

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

Linear optics refers to the study and manipulation of light in a linear and deterministic manner, where the response of...

A characteristic of laser output, calculated by dividing the speed of light by the linewidth of the laser beam. The temporal...

A solid-state laser consisting of active atoms or ions of a transition metal, rare-earth metal or actinide, imbedded in a...

Ratio, to the luminance of a test color, of the luminance of the spectrum color that matches the test color when mixed with...

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

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

A method of producing x-ray exposures as short as 0.03 µs; the primary application is in ballistic radiography.

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

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of...

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

A means of high resolution study through the application of soft and hard x-rays onto a sample surface in order to obtain...

The laser output refers to the generated and emitted light produced by a laser system. This output is characterized by...

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

A corrective lens system that is placed near the focal plane of a Newtonian telescope to increase its effective field of...

Transmittance of a stable solution is an exponential function of the concentration of the absorbing solute.

A type of mirage that creates a distorted vertical image of relatively flat objects so that they appear as mountains,...

A mathematical transformation used in image and video compression that changes two-dimensional representation of data into...

A gelatinous fluid that can be used as a porous thin-film coating for optical components, including laser beam collimators,...

The axes of symmetry in a crystal structure. See also biaxial crystal; uniaxial crystal.

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

A laser in which stimulated emission is triggered by the absorption by electrons of light from an auxiliary source such as a...

A fundamental law of wave scattering theory that connects the extinction cross section of a scatterer to the real part of...

A quantitative measure of the amount of radiation given off by an instrument, expressed in roentgens per unit of free air.

An endoscopic surgical instrument that includes a channel for the introduction of supplementary instruments.

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

Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging technique that measures changes in hemoglobin...

A type of distortion in which the magnification varies in different orientations, the directions of maximum and minimum...

The Weissenberg method, named after the German physicist Karl Weissenberg, is a technique used in x-ray crystallography for...

A camera copying system that can reduce originals onto 35- or 16-mm film for easy storage.

The technique by which an analog image is converted by any of several means into a finite array of points, each represented...

An arc lamp that has its cavity filled with krypton to produce a light source with unique characteristics.

A technique of using dyes during endoscopy to improve tissue differentiation. Dyes such as methylene blue, Toluidine blue...

A mode of laser printing in which each pixel is printed four times, providing sharper lines and a continuous tone from...

Simulation of radiative transfer in which each photon is generated by a source and its path through the medium is...

A probe card is a testing device used in the semiconductor manufacturing industry to evaluate and test the electrical...

A polishing machine designed to permit adjustment of the polisher speed and motion for the control of flat surfaces.

Degradation factor in coherent light systems where the amplitude of the recorded signal is decreased as the number of object...

A structured light device using a rapidly rotating laser to project a beam of light that appears to the human eye as a...

Pertaining to electromagnetic radiation, with the contributions at all wavelengths of interest weighted equally.

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

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

A means of testing optical fiber for macrobending losses by wrapping the fiber once at very low tension around a mandrel,...

Spatial light interference microscopy (SLIM) is an optical microscopy technique that belongs to the category of quantitative...

Voltage that produces current flow in the direction of lesser resistance to the steady-state direct current, i.e., from the...

The base used to hold an astronomical telescope. It may be either altazimuth, with horizontal and vertical axes of rotation,...

A technique used in radiography to determine a crystal's structure by obtaining radiographs of it in powder form, normally...

An approach to character recognition based on the structure of the character to be identified (number of straight lines,...

An optical reflector with the reflective coating applied to the front surface of the substrate. This eliminates the ghost...

A type of interferometer in which two coils of optical fiber are arranged so that light from a single source travels...

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

A convex or positive lens that serves to collect energy and direct it into subsequent system optics.

Information presented as a continuously variable relationship between a signal and a standard.

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

Term used to describe an optical surface that contacts the test glass only at its edges.

A material's ability to undergo plastic deformation, specifically elongation, without fracturing.

A plane-parallel interferometer that yields extremely high contrast over a wide range of finesse values without...

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

A discontinuous burst of laser light generated by timing or "gating'' a continuous-wave laser.

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

A method of measuring total hemispherical emissivity of the plane surface of a solid that consists of thermally isolating a...

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

A method of determining the abrasion resistance of very hard materials by passing a weighted wiper blade across them in a...

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

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

In astronomy, the relative brightness of a celestial body. Originally a scale from 1 to 6, where 1 represented the brightest...

In a charge-coupled device, the detection of charge collected by the transport register rather than by the image-sensing...

The process by which a vitreous or amorphous substance forms a crystal structure at a specified temperature.

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

The lateral distance between a vertical line drawn through the geometrical center of the distance portion of a multifocal,...

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

The use of computer systems for monitoring and controlling industrial production.

Whole slide imaging (WSI), also known as virtual slide microscopy or digital pathology, is a technology that involves the...

Optical fiber that transmits a greater percentage of input light than does high-loss step-index fiber. Low-loss fiber...

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

Visible laser radiation, often optically expanded and collimated, used to induced temporary blindness from within a walking...

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

A shift in the apparent position of an object when an optical element is added or removed.

The smallest area of uniform brightness that can be seen by the eye. It is measured in terms of the solid angle subtended by...

That branch of astronomy concerned with the study of the moon's physical characteristics.

A material that is present or added to a sample undergoing spectroscopic analysis, to serve as an intensity reference for...

An assembly of multiple prisms that disperses incident light into its spectral components without deviating light at the...

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

A microscopic crystal found in an intricately crystallized substance that is only visible under a microscope.

An instrument capable of measuring the transmitted or reflected luminance from a very small area seen under a microscope....

Metal used in components of the crystalline semiconductor alloys indium gallium arsenide (InGaAs), indium gallium arsenide...

A type of telescope mount that permits direct azimuth and elevation adjustments.

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

Quantum sensing refers to a class of sensing technologies that leverage principles from quantum mechanics to enhance the...

A connection, typically made up of one or more cables, between a laser head and a separate power supply. Flexible pipes or...

The light spectrum formed by an explosive reaction or by the electrical explosion of a metallic wire by a strong current.

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

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

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

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

An optical wedge in which transmittance or density is a function of the location of the wedge, relative to a specific...

Method for studying absorption coefficients of low-loss materials, in which a sample is allowed to come to thermal...

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

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

A type of piezoelectric translator that uses two thin strips of piezoelectric material, one expanding while the other...

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

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

An array of lines in the infrared region of the emission spectrum of atomic hydrogen. Their wave numbers are expressed by...

An optical system that records inhomogeneities within a medium by detecting the energy refracted by that portion of the...

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

In fiber optics, the limitation on performance imposed by the amplitude of a received signal rather than distortion.

A cylindrical lens is an optical component that has different curvatures along its two orthogonal axes, resulting in a shape...

In a thermal imaging system, the smallest change in blackbody equivalent temperature that can be detected clearly by the...

A mirror blank refers to the initial piece of material from which a mirror is made. It is typically a flat or slightly...

A scanning process in which the greatest amount of radiation determines part of a spiral motion rotating in one direction.

The dielectric coefficient parallel to the director in a liquid crystal display (LCD), rather than perpendicular to the...

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

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

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

Bardeen-Cooper-Schrieffer theory of superconductivity, based on the notion that electrons with opposite momentum and spin...

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

Hydrophobic is a term used to describe substances or materials that repel or do not readily interact with water. The word...

In a local area network, a unique signal that travels from one node or station to another, providing them serially with...

1. In raster scan television, one of the two scans that are interlaced to make up a frame. 2. See field of view.

An instrument used to measure expansion of solids, liquids and gases.

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

The decay of an electrostatic charge image resulting from long exposure to the dark.

The criterion maintaining that if light follows a specific path through an optical system, it will, if reversed, traverse...

A diagnostic instrument that uses a photocathode design to see a broad range of x-ray radiation by streaking the...

In the discharge of a vacuum tube, the narrow, nonluminous region that sometimes may be found between the cathode and its...

A double block formed by placing two adjoining, equally thick sections of quartz, one being dextrorotary, the other...

In image processing, the location of edges by employing templates that respond to the first or second derivative of...

The study of flames by means of a laser emitting blue light and a spectrometer to measure the green fluorescence created by...

A mirror composed of liquid, taking advantage of the parabolic shape of a spinning liquid and the fact that the mirror's...

A polishing machine with a lens mounted on a wooden stick, allowing a very wide sweep. It is used to polish hemispherical or...

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

The observation and measurement of the flatness of a mirror surface by contacting an optical flat with the mirror. The...

In a bifocal spectacle lens, the vertical measurement of distance from the uppermost borderline of the bifocal segment to...

A lens having one or more toric surfaces. A toric surface is one having a maximum power in one meridian and a minimum power...

A motion-picture camera that can be advanced one frame at a time, either randomly or at set intervals. Used in animation and...

Optics is the branch of physics that studies the behavior and properties of light, including its interactions with matter...

An optical system in which the only image-forming elements are curved-surface mirrors; e.g., a Cassegrain lens system.

A mode of transmission whereby the sending and receiving stations operate continuously at a fixed relationship of phase and...

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

A type of internal focusing in which only the lens elements closest to the rear of the lens barrel are moved.

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

The law stating that the critical fusion frequency is approximately proportional to the logarithm of the luminance and the...

A highly stable heavy-metal fluoride glass made from the fluorides of zirconium, barium, lanthanum, aluminum and sodium.

1. That branch of optics that illustrates the theory in which q is substituted for sin q in Snell's law. Effective results...

The capacity of a chiral substance such as a crystal or molecule to rotate the plane of polarized light that is transmitted...

In optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it....

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

A telescope that uses a reflecting objective to focus an image of a distant object at a focal point.

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

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 of optical storage whereby information is encoded by molecular alterations in the interaction between the...

Optical components, usually reflectors, produced using proprietary techniques that transfer the precision of a master to a...

In visual perception, the smallest difference in illumination perceived on the average.

A light source made up of silicon carbide or carborundum. It is resistant to the negative temperature coefficient and...

Radiation consisting of more than a single wavelength in the visible region of the spectrum.

The study and measurement of spectra and their components.

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

A lens that distorts an optical image.

An interferometer spectrometer designed to measure thicknesses of thin films or layers by recording the interferogram and by...

A television system used for seeing in the dark, particularly with the use of infrared rays.

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

A type of glass that includes phosphorus pentoxide and that, unlike silica-based glass, is resistant to hydrofluoric acid.

An abundant material found in the form of quartz and agate and as one of the major constituents of sand. The silicates of...

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

A mechanical fixture, generally a rigid tube, used to confine the stripped end of a fiber or a fiber bundle.

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

Graphic representation of quantified values of image quality whose points all refer to images that are of a constant...

A projector used to project transparencies. A horizontal 8 x 10-in. stage for writing or laying down preformed...

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

A sensor generally used for infrared imaging. It consists of two chambers separated by a thin, blackened membrane. An...

The ability of the instrument to separate wavelengths that are close together, numerically equal to the ratio of the shorter...

Effect whereby two electrons lose synchronism with the accelerating field and are lost during synchronous radiation. The...

The length of optical waveguide needed to attain equilibrium mode distribution for a specified excitation condition.

Micro-optics refers to the design, fabrication, and application of optical components and systems at a microscale level....

Small tungsten lamp used in surgical instruments such as cystoscopes, and for other purposes where space is limited.

The Lorentz oscillator model is a theoretical model used in physics to describe the response of a charged particle (such as...

An emission spectrum is a graphical representation or a characteristic pattern of the wavelengths or frequencies of light...

A dark-field microscope used to view extremely small objects. These objects are suspended in a gas or liquid in an enclosure...

An image intensifier that uses electrostatics to amplify and focus the electronic image.

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

A lack of resolution in a television image as a result of smear ghosts or an insufficiently high video-frequency response....

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

That contrast level that exists between two areas whose difference in brightness is just perceivable.

A function that quantifies the performance degradation of coherent communications systems, imaging systems and all systems...

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

A solid-state panel of the photoconductor-electroluminescent type. The photoconductive layer, sensitive to x-rays, is coated...

A vacuum deposition method in which the coating material (target) is removed from the surface of the coating source...

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

The displacement of spectrum lines, as determined by the increasing distance between, and the relative velocity of, the...

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

The theory established by Christian J. Doppler in 1842 that states that the rate of change in distance between a perceiver...

A type of internal photonic connection in an integrated circuit in which a holographic grating is used to focus light at...

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

Generally, any radiation that can form ions, either directly or indirectly, while traveling through a substance.

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...

Quantum efficiency (QE) is a measure of the effectiveness with which a device or system, typically in the context of...

In astronomy, the main lobe of an antenna pattern that has a small angular extent in two mutually perpendicular directions....

A laser, which stands for "light amplification by stimulated emission of radiation," is a device that produces coherent and...

A form of prism invented by H.W. Dove. It resembles half of a common right-angle prism in which a ray entering parallel to...