Photonics Dictionary

A technique in which a beam of x-rays is directed against a crystal, the atoms of which, because of their lattice arrangement, reflect the ray in the same way as a series of plane surfaces. If the...

The law expressing the condition under which a crystal will reflect a beam of x-rays with the greatest amount of distinction or resolution and, at the same time, denoting the angle at which the...

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

A breakout cable, also known as a fan-out cable or breakout assembly, is a type of cable that combines multiple individual cables into a single, larger cable. The breakout cable is designed to...

For light incident on a plane boundary between two regions having different refractive indices, the angle of incidence at which the reflectance is zero for light that has its electrical field vector...

Crystal growth method that resembles static freeze, but that induces growth by removing the ampoule from the furnace so that the freezing-point temperature gradient is unchanged during the growth...

Brightfield refers to a type of microscopy and imaging technique in which the specimen is illuminated with a white light source, and the image is observed or captured against a bright background. In...

The manual shifting bias control of a cathode-ray tube that determines both the average brightness and the contrast of a picture.

An instrument for measuring the brightness (luminance) of a scene. It may be a spot meter, covering an area of a degree or less, or an averaging meter, covering a broad area of the scene. Brightness...

The degree to which a pixel in a digital image represents the analog brightness of the corresponding point in the original image. It is dependent largely on the number of bits devoted to representing...

Brillouin microscopy is a non-invasive imaging technique that utilizes Brillouin scattering to measure the mechanical properties of materials at the microscale. This advanced optical technique...

Brillouin scattering is a phenomenon in physics where an incident electromagnetic wave (usually light) interacts with acoustic phonons (quantized lattice vibrations) in a material, resulting in the...

An optical instrument designed to permit the visual examination of the interior of the bronchi.

A large tank filled with liquid hydrogen, with a flat window at one end and complex optical devices for observing and photographing the rows of fine bubbles formed when a high-energy particle...

Specially designed optics for the observation and photographing of hydrogen in a bubble chamber.

The photographic recording of gas bubbles produced when particles traverse liquid hydrogen in a bubble chamber.

A device that functions throughout the continuous radiation of a linearly polarized plane wave, and whose nonreciprocity arises from the Faraday rotation of linearly polarized radiation.

A photometer screen that contains a diaphragm of paper or parchment with a translucent central spot of oil or paraffin.

A C-mount lens refers to a specific type of lens commonly used in machine vision, surveillance, microscopy, and other imaging applications. The "C-mount" designation refers to the standard interface...

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

A calcium indicator is a molecule that is sensitive to changes in calcium ion (Ca2+) concentrations in biological systems. These indicators are commonly used in various fields, including cell...

A hygroscopic powder used in the photographic process.

A lamp whose output can be traced to a standard light source.

The coefficient termed by Callier as the ratio between the density of photographic negatives measured by parallel light and that measured by diffuse light, due to scattering effects. This effect is...

Calorimetry is a branch of science that involves the measurement of heat flow in physical or chemical processes. It encompasses various techniques and instruments used to quantify heat transfer,...

A portable instrument that uses a four-sided reflecting prism or set of mirrors to create a duplicate image of an object on a horizontal sheet, on which outlines of the subject may be traced by hand.

A forerunner of the modern camera, this instrument had a focusable lens that produced a sharp image on the enclosure opposite the aperture but had no photosensitive material to record it.

The use of the photographic process to produce precision copies of an original image that are many times smaller in size. One of its many applications is in microcircuitry.

An apparatus, designed for use with a camera, that is used to rapidly open the path from lens to film, to maintain the opening throughout exposure and to close the opening in rapid succession. The...

The electron beam tube of a television camera that converts an optical image into a pattern of electrostatic charges and then scans the pattern to produce a corresponding electronic signal for...

A light-tight box that receives light from an object or scene and focuses it to form an image on a light-sensitive material or a detector. The camera generally contains a lens of variable aperture...

An electric discharge between two carbon rods that are touched together to start the arc and then separated slightly. The light comes from the heated carbon vapor. High-intensity arcs use cored...

Carbon fullerenes are a class of carbon-based molecules composed entirely of carbon atoms arranged in a hollow, closed, cage-like structure. The most well-known fullerenes are spherical and are often...

Carbonization is a process in which organic materials are heated in the absence of air, leading to the decomposition of the material and the production of carbon-rich residue. During carbonization,...

A system that generally uses a photodetector to decode punched cards for information, or for input to a computer, by sensing the light transmitted through the punched holes.

Carrier injection refers to the process of introducing charge carriers (either electrons or holes) into a semiconductor material. Semiconductors are materials with electrical conductivity between...

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

A heterochromatic photometric process using successive comparison of similar chromaticities and the calculation of relative luminances of unlike chromaticities as the product of ratios of luminances...

A shower of cosmic rays whereby a high-energy electron produces one or more photons that convert into electron pairs, the secondary electrons producing the same effects as the primary. As the process...

The Casimir force is a quantum phenomenon that results in an attractive force between two closely spaced uncharged conductive surfaces. This force arises from the quantum vacuum fluctuations of the...

A two-mirror lens design used in astronomical telescopes, the primary being a parabola, the secondary a smaller hyperbola. The image formed is free of spherical aberration and color and is located...

A container designed to hold recording material (film, video- and audiotape) so that when it is loaded into a recording instrument, the recording material is threaded simultaneously.