Photonics Dictionary

The all-encompassing noise associated with a given environment, usually being a composite of a number of sources, far and near.

The transparent fluid that fills the portion of the eye between the cornea and the eye lens (the anterior chamber).

An aspheric lens is a type of lens whose surface profiles deviate from the traditional spherical shape. Unlike spherical lenses, which have a constant curvature across their surfaces, aspheric lenses...

The analysis of the atomic structure of a sample by means of a source radiation that is absorbed and emitted by the sample with lines corresponding to the number and arrangement of atoms. Generally a...

The number of molecules in one gram mole of a substance, numerically approximated by 6.02 x 1023.

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

Degradation factor in coherent light systems where the amplitude of the recorded signal is decreased as the number of object points is increased, resulting in poor noise performance.

The ratio of the number of bits received incorrectly to the total number of bits transmitted digitally in a system.

A supporting member used to hold optical parts during grinding and polishing. It also describes the assemblage of optical parts on the supporting member; e.g., a block of lenses or block of prisms.

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...

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 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 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...

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...

The number of bits used to represent a character.

Camera Link HS (high speed) is a standard developed for high-speed digital data transmission in machine vision and industrial imaging applications. It is an evolution of the original Camera Link...

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...

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...

Cathode radiant sensitivity refers to the ability of a photocathode to convert incident radiant energy, typically in the form of light, into an electrical signal. Photocathodes are components used in...

A fiber optic end plate constructed by drawing a bundle of parallel fibers embedded in glass and cutting it into thin slices. These slices are assembled in a plane and heated to produce a...

A CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images into electronic signals. It is a key component in digital cameras, camcorders,...

A rotating chamber that can be spun at different speeds to generate great radial forces used to simulate different gravity loads.

The number of channels per unit bandwidth handled by a single optical fiber.

Chemical vapor deposition (CVD) equipment refers to a class of specialized apparatus used in the process of chemical vapor deposition, a technique for depositing thin films of various materials onto...

In morphological image processing, a series of dilations followed by the same number of erosions.

A CMOS image sensor, short for complementary metal-oxide-semiconductor image sensor, is a type of semiconductor device used to capture visual information and convert it into electrical signals for...

A coherent fiber bundle (CFB), also known as a coherent fiber optic bundle, is an assembly of multiple optical fibers arranged in a specific geometric pattern to maintain the spatial coherence of...

Cold atoms refer to atoms that have been cooled to extremely low temperatures, typically in the microkelvin (µK) to nanokelvin (nK) range, close to absolute zero (0 Kelvin or -273.15°C). At...

A lens made up of a number of lens elements arranged into two or more groups.

Also called color blocking. The formation of a block by making optical contact between a number of optical elements and a large optical flat.

The maximum number of users who are using a given communication channel. Typically, the number of users at any given time is below this maximum, with the contention rate representing a worst case...

In optical character recognition systems, the identification of a character facilitated by means of known factors governing its appearance in a particular context; e.g., the first character in the...

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

Calculation of the probability of an interaction between two types of particles, such as light absorption, excitation or energy transfers. The probability that one incident particle will interact as...

Standard maintained by the International Commission on Radiological Units as a unit of radioactivity defined as the quantity of any radioactive nuclide in which the number of disintegrations per...

An organizational method used in optical design computer programs. The technique produces one number (merit function) to measure the state of correction of an optical system. This number, which is...

The number of unique ways in which a part can move in an alignment system. In static alignment, there are six: one in the direction of and one in rotation about each of the X, Y and Z axes. In...

A diagram in which the variable frequencies of a spectral band system are plotted corresponding to ascending values of the quantum numbers of the upper and lower energy levels.

A detector array refers to a collection of individual detector elements arranged in a two-dimensional grid or matrix format. Each element within the array is capable of detecting electromagnetic...

A tool made by imbedding small particles of diamond in the working edge. In the optical field, the most commonly used diamond tools are glass saws, cup-shaped tools for curve generators, and diamond...

A polarizer that consists of dichroic polarizing material embedded in a plastic sheet, and that transmits light that is almost completely plane polarized with an intensity that is half that of the...

A number that indicates the magnitude of the shift in a solid of positive and negative charges in opposite directions when a voltage is applied across the solid.

A diffraction grating is an optical component consisting of a surface with a periodic structure of equally spaced, parallel grooves or rulings. These rulings act as an array of closely spaced slits...