Photonics Dictionary

Birefringence is an optical property of certain materials that causes them to exhibit different refractive indices for light of different polarizations. In other words, when light passes through a...

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

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

In ophthalmic practice, an instrument that determines the boundaries of the field of view. It is composed of a 2-m square of black velvet with a white spot center at which the patient, 1 m away,...

A blackbody source, often simply referred to as a blackbody, is a theoretical or practical physical object that absorbs all electromagnetic radiation incident upon it and emits radiation in a...

A piece of glass, quartz or other transparent material formed roughly by molding or cutting into the approximate shape and size of the finished part.

1. A plane that forms one side of the groove ruled on a diffraction grating. 2. To form the individual grooves of a grating with flat smooth faces, inclined to the surface by an angle known as the...

An extended bubble or seed on glass, elliptically shaped and more than one-quarter inch (6.3 mm) in length.

An adhesive used to hold optical elements to blocking tools. It is usually a thermoplastic substance such as resin, beeswax, pitch or shellac.

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

An instrument used to support optical parts to be cemented, or to be mounted in plaster.

A blue diode laser is a type of semiconductor laser that emits light in the blue wavelength range of the electromagnetic spectrum, typically between 400 and 500 nanometers. Diode lasers are compact,...

A blur circle refers to the out-of-focus region in an image captured by an optical system. When an object in a scene is not in perfect focus, its image is spread out into a circular shape on the...

The law given by the formula: that is, the frequency of radiation emitted or absorbed by a system when E2 and E1 are the energies of the states among which transition takes place, and h is...

A thermometric instrument used for the detection and measurement of radiant energy. Its essential component is a short narrow strip covered with a dead black absorbing coating and mounted at the...

A constant equal to the universal gas constant divided by the Avogadro number. It is approximately equal to 1.38 x 10-23 J/K and is commonly expressed by the symbol k.

A device for the internal inspection of hard-to-get-at mechanical parts, such as rifle barrels, sewer pipes, oil wells, or gas mains. The long narrow tube used contains a telescope system with as...

A Bose-Einstein condensate (BEC) is a state of matter that forms at temperatures close to absolute zero. It is named after Satyendra Nath Bose and Albert Einstein, who independently predicted the...

The simplest, most inexpensive type of camera, which is shaped as an oblong or square box, containing the simplest lens, shutter and viewfinder, as well as the most elementary means of registering...

An instrument for detecting and analyzing repetitive signals. Using a fixed time delay or "gate," the input signal is sampled numerous times and averaged to increase the ratio of the...

A spectrophotometer having a pair of identical collimators with two Glan polarizing prisms, one fixed in azimuth and the other rotatable, set in one collimator. A Brace prism serves as the dispersive...

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...

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

An experimental model of an electrical circuit or complex assembly; a prototype.

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...

Electromagnetic radiation that is emitted by an electron as it is accelerated or decelerated while moving through the electric field of an ion.

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...

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...

Broadband dielectric mirrors, also known as broadband mirrors, are optical coatings designed to efficiently reflect or transmit light over a broad range of wavelengths. These mirrors are constructed...

The behavior of microscopic solid particles suspended in a fluid, first observed by botanist Robert Brown in 1827 as a continuous random motion.

A conical or cylindrical package of light rays emanating from a common point on the object.

The law stating that the amount of chemical change produced is proportional to the amount of light absorbed. Actually, the change is also dependent on the intensity of light -- a fact named the...

A high-frequency pulse-rate laser with an output limited by the heat capacity of the laser medium. Instead of having continuous cooling, the laser operates until the medium reaches a maximum...

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

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 standard lens interface initially made for 16mm movie cameras and now used primarily on closed-circuit television cameras. It is a 1-in.-diameter, 32-thread-per-inch interface with a...

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

A doubly refracting mineral used to produce polarizing prisms. It is uniaxial negative and in the trigonal division of the hexagonal system of crystals. Its indices are e = 1.486, w = 1.658; its...

An optical material used in place of crown glass to produce lenses with extraordinary correction of chromatic aberrations. Its high coefficient of thermal expansion and its tendency to absorb...

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...

Any known value derived from standard analysis that serves as a reference to the accuracy of an instrument or process in determining one or more variables.