Photonics Dictionary: C

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.

That part of an infrared detector-Dewar assembly that limits the solid angle viewed by the sensor; it is maintained at a uniformly cold temperature so that no thermal energy is emitted. Also known as...

The application of coating without heating of the substrates.

A means of illumination from which the infrared component has been removed by absorption or reflection filters within the condenser system.

Collaborative Robot (Cobot): Unlike traditional autonomous robots, which usually work by themselves, a collaborative robot is programmed to work with humans, such as a guide or an assistant. They can...

Category inclusive of all radiation that is incited electronically, except laser radiation, as a function of the application of laser power to a system.

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

A convex or positive lens that serves to collect energy and direct it into subsequent system optics.

A positive lens located at or close to an intermediate image plane. The collector refracts off-axis light bundles, directing them into the apertures of subsequent optics.

A ring dye laser that uses prisms and a saturable absorber within the laser cavity to shape and shorten the pulses generated. Counterpropagating modes oscillating simultaneously in the ring...

Radiation in which every ray from any given object point can be considered to be parallel to every other. This is never completely the case: The light from a star is really diverging, and all...

1. The process of aligning the optical axes of optical systems to the reference mechanical axes or surfaces of an instrument. 2. The adjustment of two or more optical axes with respect to each other....

An optical instrument consisting of a well- corrected objective lens or mirror with a light source and or object/image (i.e. illuminated slit or retical) at its focal plane. Collimators are used to...

A method of exciting a laser by coupling it directly to another laser.

The broadening of spectral lines due to the collision of radiating particles with one another and the resulting interruption of the radiative process.

A method of lasing in which free electrons in a laser-produced plasma collide with neonlike ions to excite electrons to states that decay at different speeds, producing a population inversion.

A colloid is a mixture in which one substance of microscopically dispersed insoluble particles is suspended throughout another substance. The particles in a colloid are larger than those in a...

A polariscope used to demonstrate strain inherent in a piece of glass.

The attribute of visual experience that can be described as having quantitatively specifiable dimensions of hue, saturation, and brightness or lightness. The visual experience, not including aspects...

A test used to measure the degree of fading of different colored materials, especially those involving organic dyes, which tend to fade when exposed to bright sunlight, to a damp atmosphere or to...

Certain color centers in the alkali halides have been optically pumped to produce efficient tunable pulsed and continuous-wave (CW) lasers emitting in the range of 0.8 to 3.3 µm.

A color center, in the context of materials science and condensed matter physics, refers to a specific type of crystallographic defect in a crystalline structure that introduces color to the...

An early graphic scheme of colors in which saturated spectral colors are plotted around the circumference of a circle. Complementary colors face each other across the circle's diameter.

1. A device used in chemistry to compare the colors of solutions held in flat-bottomed tubes and viewed along the length of the tube. Often a solid glass plunger is moved along one of the tubes to...

A filter that serves to alter the color temperature and the mired value of the radiation emitted by a source.

The reduction in longitudinal, lateral and secondary chromatic aberrations in a lens or lens system.

The transmission of a color photograph by separating the colors into varying intensities of red, blue and green, and then sending separate transmissions of the three color signals to a receiving...

A unit that converts images to the standard NTSC format for use with video recorders, projectors and discs.