Photonics Dictionary

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.

The recording of three or more separate holograms having a different color on a medium, so that illumination with a tricolor beam yields three separate wavefronts, each representing one of the...

Condition in which two stimuli appear to match in color to a specified observer, or in which two objects appear to match in color to a specified observer when illuminated by a specified source.

An instrument providing a continuous measure of color.

Equipment for testing an observer's color vision. Some tests require the identification or ordering of colored samples. The commercially available examples include: the Ishihara plates, on which...

Film that produces color negatives or transparencies by the use of three emulsions, one coated over the other, that are each sensitive to one of the colors red, blue or green.

A CIE index describing the changes in color of standard test objects when the illumination is changed from a standard to a test illuminant.

An instrument that uses a beam of light to scan a color transparency, and three differently filtered photosensors to record the transmitted beam, as a means of producing three exposed separation...

The detection and analysis of the relative response of a material to light over the range of wavelengths.

The entire range of colors a specific color model can produce, represented as a three-dimensional solid.

A television system that is capable of producing an image whose colors approximate the colors of the original, by the use of additive color mixing of the three primary colors.

A colorimetric concept related to the apparent visual color of a source (not its temperature). For a blackbody, the color temperature is equal to the temperature in kelvin.

A device containing two photocells behind deep red and blue filters to measure color temperatures. The amplifier gain is adjusted to give a set reading of one photocell; the reading of the other is a...

A thermogram in which temperature values are displayed in discrete thermal bands, each band possessing a distinct color.

Color vision refers to the ability of organisms to perceive and distinguish different wavelengths of light as different colors. It is a sensory ability that allows humans and many other animals to...

Situation in which the observer requires fewer than three independent stimuli to make color matches. Dichromats require only two stimuli and are classified as protanopes and deuteranopes (both...

An emulsion that can record colored light.

A type of compound microscope that uses three visible wavelengths to translate details produced by invisible radiation.

A substance such as a dye or pigment that is used to alter the color of light.

A colorimeter is a device used to measure and quantify the color characteristics of an object or a light source. It provides objective and standardized color information, typically expressed in terms...

A photometer that uses a set of color filters to measure the intensity of light in various regions of the spectrum.

Ratio, to the luminance of a test color, of the luminance of the spectrum color that matches the test color when mixed with white light.

Colorimetry is the science and technology of quantitatively describing and measuring colors. It involves the precise evaluation of color attributes such as hue, saturation, and brightness, using...

Transparent media which, when placed in front of a light source, change their color as a result of the selective absorption of some of the light.

The chromatography method in which the stationary phase is supported in or on an inert packing in a column, through which the mobile phase passes.

A lens aberration, resulting from different magnifications in the various lens zones, that occurs in that part of the image field that is some distance from the principal axis of the system....

A filter that passes a series of wavelength regions that are at equal distances from one another, such that its output resembles the teeth of a comb. In video transmission, a comb filter is used to...

A semitransparent mirror in an optical system that combines two or more output beams into a single coaxial beam.