Ray tracing is a rendering technique used in computer graphics to simulate the way light interacts with objects in a scene. It involves tracing the path of rays of light as they travel through a virtual environment and interact with surfaces,...

Azimuthal polarization refers to a specific polarization state of light where the electric field vector of the...

An eyepiece having a rotating index or cross wire linked to an external 360° scale to allow measuring of angles in an...

Total internal reflection fluorescence (TIRF) microscopy is an advanced fluorescence microscopy technique that leverages the...

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

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

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

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

A 45-90-45° reflecting prism whose surfaces form the 90° angle reflecting the light beam through a total angle of 180°. The...

Flux per unit solid angle and per unit area measured normal to the direction of propagation of the flux.

A small defocused Galilean telescope mounted in a hole in a door. Viewed from inside through the positive lens, a wide-angle...

1. A plane that forms one side of the groove ruled on a diffraction grating. 2. To form the individual grooves of a grating...

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

Also known as ocular. The lens system used between the final real image in a visual optical system and eye. It acts as an...

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

A hemispherical covering that is rotatable about a central axis. There is a slit opening along one side wide enough to allow...

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

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

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

An acousto-optic modulator (AOM) is a device that utilizes the interaction between sound waves and light waves to modulate...

Quantum sensing refers to a class of sensing technologies that leverage principles from quantum mechanics to enhance the...

The sine of the vertex angle of the largest cone of meridional rays that can enter or leave an optical system or element,...

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

The angle formed between a refracted ray and the normal to the surface. This angle lies in a common plane with the angle of...

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

A theoretical instrument conceived of as a box that receives a beam of radiation of any arbitrary polarization angle and...

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

The angle subtended by two points or lines that are just far enough apart to be distinguished as separate. The ability of an...

A disc composed of a series of holographic optical elements that diffract light at various angles. When spinning, a raster...

Light striking a surface at an angle perpendicular to the surface.

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

Quantum entanglement is a phenomenon in quantum mechanics where two or more particles become correlated to such an extent...

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

A Fresnel lens is a type of optical lens that consists of a series of concentric grooves or steps carved into a flat, thin...

Multimode straight fiber capable of transporting linearly polarized light with any incident polarization angle, and in which...

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

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

The angle that lies between the direction of an incident light beam and any resulting diffracted beam.

A laser rangefinder is a device that uses laser technology to measure the distance between the device and a target. It...

SI unit of luminous intensity. It is defined as one sixtieth the normal intensity of one square centimeter of a blackbody at...

The letter form used on visual performance test charts. The overall letter height is equal to five times the thickness of...

A cathode-ray display where information is represented visually as spots. Each spot's location is represented by a...

A double-plate device used to transmit polarized light and form interference fringes of the light, thus indicating its...

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

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

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

Chip-on-board (COB) lights refer to a type of LED lighting technology where multiple LED chips are directly mounted onto a...

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

A precise telescope set on a pair of rotation axes, the horizontal and vertical axes equipped with two divided circles. One...

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

A still or motion-picture camera designed to photograph through a microscope. Photomicrographic equipment usually contains a...

Geometrical partition possible with a sphere that can be four, six, eight, 12 or 20 solid-angle wedges. Each platonic mass...

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

An optical combiner, in the context of optics and display technologies, refers to a device or component that combines...

In biaxial crystals, the principal angle that bisects the smaller angle between the optic axes.

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

The law expressing the condition under which a crystal will reflect a beam of x-rays with the greatest amount of distinction...

Minimum object distance, often abbreviated as MOD, refers to the closest distance at which a camera lens or optical system...

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

Sometimes referred to as the surface normal or 'surface norm'; the normal is an axis that forms right angles with a surface...

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

A five-sided prism containing two reflecting surfaces at 45° to each other, and two refracting faces perpendicular to...

Luminous flux emitted from a surface per unit solid angle per unit of area, projected onto a plane normal to the direction...

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

Relative power distribution as a function of position or angle.

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

Any of the constants that relate the tendency of the director to remain parallel to restoring torques throughout the media....

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

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

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

The angle through which a beam is deflected.

1. That branch of optics that illustrates the theory in which q is substituted for sin q in Snell's law. Effective results...

The angle through which a ray of light is deviated by a refracting or reflecting surface, or a prism; the angle between an...

The Weissenberg method, named after the German physicist Karl Weissenberg, is a technique used in x-ray crystallography for...

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

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

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

Ellipsometry is an optical technique used to characterize the properties of thin films and surfaces. It is based on the...

A diagram used to represent the trichromatic variables of the components in a three-color combination.

A variation of tomography, which is a means of visualizing any one of a large set of parallel planes in the patient. A...

The second adjustable iris diaphragm in an optical system. In the common microscope condenser system, it usually is located...

The angle between the light input propagation vector and the optical axis of an optical fiber or fiber bundle.

The flat or angled surface, usually fine-ground, that limits the aperture of a lens or prism surface.

A fast, wide-angle lens used in television and photographic cameras, with excellent overall correction, but subject to...

A prism formed by dividing a Nicol prism in a plane parallel to the path of vibration of the transmitted light and taking...

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

A prism produced by severing a Nicol prism and reconstructing the polarization angles of the two halves so that they are...

An aberration of a lens system caused by an increase in lens focal length as the field angle increases. The amount of...

The positioning of two Nicol prisms so that their axes are at right angles to each other. With this arrangement, light...

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

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

Descriptive of the radiant power of visible light modified by the eye response. It is the measure of the flow of visible...

A holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists...

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

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

A symmetrical, very wide-angle lens. Well-corrected for spherical aberration and color, the Topogon can cover fields up to...

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

A family of specialized instruments used by ophthalmologists and optometrists to study a patient's eyes and prescribe...

The maximum angle of view that can be recorded by a camera. Field is a function of lens focal length and film format.

Half the vertex angle of the cone of light emitted by a fiber.

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

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

Also referred to as the opposition surge, the opposition effect is a photometric phenomenon in which a rough retroreflective...

The angle between the most divergent rays that can pass through the lens to form an image. In a birefringent crystal light...

The triangle in a chromaticity diagram joining the chromaticities of the NTSC phosphors, and containing all chromaticities...

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

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

A glass rhomb that is used in photometry to compare two illuminated surfaces. This is accomplished by the rhomb's angles,...

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

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

A retroreflector is an optical device or structure that reflects incident light or electromagnetic waves back to their...

An instrument that measures the angle at which a prism can couple laser light into an optical waveguide; used to determine...

The deviation from the ideal case where a circular variable filter is located at a given wavelength along a radial line (or...

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

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...

A mount that uses a floating suspension and a motor-driven gyroscope to keep a motion picture or still camera at a set angle...

1. Viewed with one eye. 2. Describing an image as viewed from a single angle.

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

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

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

The use of a specialized optical microscope designed to provide a more three-dimensional view of a sample. Stereomicroscopy...

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

A Laurent polarimeter is an instrument used in optics for measuring the rotation of plane-polarized light caused by...

An optical instrument used to determine the distance to a target being viewed. Two similar optical systems view the target...

1. The angle between two vectors that represent two simple periodic quantities that vary sinusoidally and that have the same...

The solid angle of a detector or system pupil as seen by the source.

That part of an infrared detector-Dewar assembly that limits the solid angle viewed by the sensor; it is maintained at a...

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

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

Lensless microscopy, also known as computational or holographic microscopy, is an imaging technique that captures and...

In a cathode-ray tube, the deflection of the beam of the tube over an angle that surpasses the angle that subtends the...

The separation of unpolarized light into two plane-polarized elements by a doubly refracting crystal. When a crystal, such...

An echelon in which the dihedral angle between the faces of the groove is 90°.

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

The final correction of a polished surface or of an angle to the specified precision.

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

The smallest area of uniform brightness that can be seen by the eye. It is measured in terms of the solid angle subtended by...

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

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

Fluorescence imaging technique in which the excitation light from the objective is directed into the sample producing...

A polygonal mirror, also known as a multifaceted mirror or facet mirror, is a type of optical component used in various...

In a birefringent material, the index of refraction varies with the direction of vibration of a lightwave. That direction...

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

A 30-60-90° spectrograph prism that is coated on the surface opposite the 60° angle with a reflecting film.

The incident ray, the normal to the refracting surface at the point of incidence of the ray at the surface, and the...

In optics, a plane that emits a flux proportional to the cosine of the angle of the normal; dense opal glass is an example.

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

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

Also known as corner-cube reflector or retrodirective reflector. Three reflecting surfaces, perpendicular to each other,...

A common aberration in lenses covering large fields of view; it results in images of objects near the edge of the field...

The angle subtended by the mean distance of the Earth from the sun at the distance of a given star from the sun.

A type of high-speed photographic shutter that uses Faraday rotation to produce exposure times as fast as 1 microsecond. It...

Scalar diffraction theory is a simplified approach used to describe the propagation of electromagnetic waves, particularly...

The entrance slit, also known simply as the slit, is an essential component in optical instruments such as spectrometers and...

The angle subtended by an object at the point of observation.

The least space between two parallel lines that can be discriminated as a gap to the human eye. It is measured in terms of...

The measured planar or solid angle of related aspects of an optical system with respect to an optical axis.

Holographic tomography is an advanced imaging technique that combines holography and tomography to provide three-dimensional...

The Golgi staining technique (also called the black reaction) makes it possible to look at the nervous system by rendering...

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

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

A family of lenses commonly used in scan systems for reading or printing documents. The lens must be designed such that the...

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

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

A holographic camera, also known as a holographic imaging system or holographic recorder, is a specialized device used to...

A spectrometer or autocollimator used to measure prism angles.

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

In an optical system, the gradual reduction of image illuminance as the off-axis angle increases, resulting from limitations...

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

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

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

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

The angular difference in the direction of an object as seen from two points of observation. The angle subtended at the...

The angle between a light ray emerging from an optical system and the optical axis of that system.

The unit angle, within an arc of a circle, equal to the radius of the circle (180/p°, numerically).

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

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

A parallel plate of glass in such a position that the refracted and reflected rays of incident parallel light are mutually...

A type of 45-90-45° prism used to bend a beam of light through a right angle with the surfaces forming the 90° angle...

A statistical analysis of facts obtained when the intensity of x-ray diffraction is calculated at different angles. In this...

A general term referring to the situation in which an image is not a true-to-scale reproduction of an object. The term also...

A light ray that has had its direction altered because of its traversing an air-to-glass interface at some angle. In an...

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

A pair of stars (double star) that can be seen separately with a telescope, generally by setting a filar micrometer for the...

A handheld navigational instrument used to measure the elevation angle of celestial bodies such as the sun. An image of the...

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

Having three unequal angles perpendicular to each other.

A narrow channel created by cleaving a crystal made of alternating layers of gallium arsenide and aluminum gallium arsenide,...

On a display monitor, a small, mobile rectangle, cross-hair or pointer that locates a feature in an image that is the object...

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

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

Totally coherent radiation is produced by a purely monochromatic point source. In the real world the energy will have a...

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

A device that obliterates the polarization of a polarized beam by reflecting the beam in all directions at right angles to...

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...

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

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

Flux per unit solid angle.

A plane (through the focal point) at right angles to the principal axis of a lens or mirror; that surface on which the best...

A reflecting prism that inverts the image. The image is reflected four times internally and emitted laterally. The prism is...

A glass or metal measurement tool having a precisely calibrated angle between two of its faces.

A perfectly diffusing surface; the intensity of the light emanating in a given direction from any small surface component is...

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

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

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

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

A two-dimensional scanning process, in which a slow sector scan, propagated in one direction, is superimposed at right...

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

Optics is the branch of physics that studies the behavior and properties of light, including its interactions with matter...

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

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

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

Also known as the Bragg spectrometer. A system used for the x-ray analysis of crystal structure. In the instrument, a...

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

An angle formed by the lines of sight of both eyes when focusing on an object. Also, the rate at which a ray approaches the...

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

Mie scattering, named after the German physicist Gustav Mie, refers to the scattering of electromagnetic radiation (such as...

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

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

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

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

The reflection that occurs within a substance because the angle of incidence of light striking the boundary surface is in...

An instrument designed to measure angles in azimuth; used in general topographic work and military gunnery.

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

The ability to see over large angles of view.

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

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

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

The law stating that the angle of reflection is equal to the angle of incidence, the incident ray, reflected ray and normal...

Translucent collector developed to compensate for the partial blocking of a flat surface's collection angle that normally...

A multiple-beam interferometer, usually consisting of two flat plates, with high reflective ability. The plates are set...

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

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

A dichroic mirror, also known as a dichroic beamsplitter or interference filter beamsplitter, is an optical device that...

The angle at which a given mode propagates down an optical fiber.

The least angle of incidence at which total internal reflection takes place. The angle of incidence in a denser medium, at...

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

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

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

The radiant energy emitted within a time period per unit solid angle, usually measured in watts per steradian.

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

An organizational method used in optical design computer programs. The technique produces one number (merit function) to...

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

A wide-angle lens is a type of camera lens that has a shorter focal length than a standard or normal lens, allowing it to...

The effect by which sufficiently small particles will scatter blue light at right angles to the incident beam. This...

Light striking a surface at an angle almost perpendicular to the normal.

The term quantum refers to the fundamental unit or discrete amount of a physical quantity involved in interactions at the...

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

The apparent visual angle that divides intrabeam viewing from extended-source viewing.

A device containing two opposed quartz wedges of equal angle, one wedge being movable along its length by a micrometer...

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

Family of deterministic models of plant canopy reflectance that provides deterministic formulation for each necessary...

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

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

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

The angle between the initial and final paths traveled by a scattered particle or photon.

A technique whereby the sample is illuminated by a hollow cone of light larger than the acceptance angle of the objective,...

Instantaneous field of view (iFOV) is a term commonly used in the context of remote sensing, imaging systems, and optical...

The astigmatism in a lens system that results when light enters the system at an oblique angle.

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

Law relating the illuminance (or irradiance) of a surface to the cosine of the angle, q, between the normal to the surface...

The angle measured between the focal surface containing the image and a plane normal to the optical axis.

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

Equivalent to 10-6 radian, where 1 radian equals 180/pi degrees. A rod 1 km in length will be moved by an angle of 1...

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

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

A high-quality, narrow-angle lens of high aperture designed for low magnification in the recording of cathode-ray tube...

A piece of uniform birefringent material placed at a 45° angle to the plane of polarization in a polarizing microscope...

A surface that is swept out by revolving a circle about an axis that lies in the plane of the circle but that does not...

A mirror that supplies equal reflectance for both the S-polarization and the P-polarization of a laser for a defined angle...

A mirror employed with a very high incidence angle to form a pair of coherent light sources by reflection, and therefore...

One of two types of solar time - the other being apparent solar time - the mean solar time is the time measured by the...

The angle formed between the normal to a surface and the reflected ray. This angle lies in a common plane with the angle of...

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

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

A laser using a dye solution as the active medium whose resonator is formed into a ring (or a triangle or another shape) by...