Photonics Dictionary

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...

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...

Colloidal quantum dots (CQDs) are nanometer-sized semiconductor particles that are dispersed in a colloidal solution. These quantum dots have unique optical and electronic properties due to their...

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 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...

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...

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.

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.

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 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.

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...

An acronym for communications intelligence, referring to the collection of communications signals in the VHF and UHF frequency ranges (20 to 1200 MHz).

A laser warning and countermeasure system containing a sensor that indicates the direction of a laser beam, and analytical instruments to determine pulse code, repetition frequency and wavelength.

The heat-treating method in which the index of refraction of glass is fixed near or at its maximum value by holding the glass for different periods at suitable degrees of heat below the range of...

A deliberately nonlinear amplitude modulation that strengthens weak signals and reduces strong signals for transmission.

1. An eyepiece or magnifier with a scale at its image plane. That scale is placed in contact with an object, permitting direct measurement of its size. 2. Also called traveling stage and traveling...

A device used for the comparison of spectra used, in turn, for the comparison of elements, such as the absorption lines in the spectra of stars and the spectra of elements in the stars being observed.

A microscope eyepiece designed for use with apochromatic objectives. Since apochromatic objectives are undercorrected for lateral color, these eyepieces are overcorrected for that aberration.

A filter used in photography to change the spectral composition of light entering a camera, or to adjust color balance during printing.

Complementary metal-oxide-semiconductor (CMOS) refers to a technology used in the fabrication of integrated circuits, particularly semiconductor devices like microprocessors, memory chips, and image...

1. A constituent part. It may consist of two or more parts cemented together, or with near and approximately matching surfaces. 2. The projection of a vector on a certain coordinate axis or along a...

A type of video signal in which the luminance and chrominance portions of the signal, or the luma and chroma, have been combined according to standards such as NTSC, PAL or SECAM.

A transducer composed of more than one high-pass, bandpass, low-pass or band-elimination filter.