Photonics Dictionary

A method of improving the signal-to-noise ratio of an interferogram by adding another interferogram to it.

Coagulation refers to the process of transforming a liquid, particularly blood or a solution containing dispersed particles, into a solid or semi-solid state. This term is most commonly associated...

Optical elements that have been coated with one or more layers of dielectric, or metallic material. These coatings serve to reduce or increase reflection from the surface, and to protect the surfaces...

A type of cable made up of two conductors; one conductor is inside of and concentric with the other.

A jet of inert gas along a laser welding beam's axis that cools, protects or cleans the work surface.

CoaXPress (CoaXPress or CXP) is a standardized digital interface and communication protocol used primarily in machine vision and industrial imaging applications. It enables high-speed data...

Glass that transmits near-ultraviolet radiation but is opaque in the visible region. Also known as woods glass.

A device that combines the functions of encoder and decoder.

An imaging process in which the single opening of a simple pinhole camera is replaced with many openings called, collectively, the aperture. The recorded picture, which consists of many overlapping...

A reticle carrying patterns of various forms that can be rotated in an optical beam to cause variations in the intensity of the beam. It also is used in infrared detectors to scan the object field...

An image that is not immediately recognizable but scrambled.

A plane mirror mounted on a polar axis that lies parallel to the plane of the mirror. When the mirror is rotated once in 48 hours, celestial objects can be made to appear stationary and are...

That length over which energy in two separate waves remains constant. With respect to a laser, the greatest distance between two arms of an interferometric system for which sufficient interferometric...

A technique whereby two laser beams, one at an excitation wavelength and the second at a wavelength that produces Stokes Raman scattering, interact coherently in a sample, producing a strong...

Coherent anti-Stokes Raman spectroscopy (CARS) is a powerful technique used in spectroscopy to probe molecular vibrations in a sample. It is based on the Raman effect, which involves the inelastic...

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...

A light source that is capable of producing radiation with waves vibrating in phase. The laser is an example of a coherent light source.

The manifestation of light from scatterers outside the plane of the object in coherent light systems. The output of these systems is often marred by this noise.

The use of phase conjugation or other methods to increase the power density of a laser beam under adverse atmospheric conditions.

Radiation in which the phase relationship between any two points in the radiation field has a constant difference, or is exactly the same in either the spatial or the temporal mode throughout the...

Electronic circuit capable of distinguishing the pulses emitted by separate counters in a given time phase and determining whether the pulses were emitted by the same particle or correspond to a...

A compound prism consisting of an assembly of small prisms cemented together that is used in a coincidence rangefinder to transmit the images from the two objectives to a single eyepiece for viewing.

An optical instrument used to determine the distance to a target being viewed. Two similar optical systems view the target via 45° mirrors at the ends of a fixed baseline. One system creates the...

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 cathode that emits electrons, not with the influence of heat radiation, but by means of a high-voltage gradient at its surface.

A method of applying antireflection coatings to optics that avoids the elevated temperatures normally used. A cold coating will not be as durable as a normal coating.

A cryogenically cooled component incorporated into the Dewar of an infrared detector assembly to maintain the sensing elements at the proper temperature (77 K or colder).

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

A mirror whose coating serves to reflect visible radiation while transmitting the infrared.