Photonics Dictionary

The monochromatic transparency effect produced by the immersion of a finely powdered substance (e.g., glass or quartz) into a liquid with a similar refractive index.

A transparent powdered solid immersed in a liquid or plastic of similar refractive index but widely different dispersion; used to isolate narrow spectral regions.

1. Attribute of a visual sensation that permits a judgment to be made of the amount of pure chromatic color present. 2. The portion of a composite video signal that carries the chrominance values,...

Chromatic aberration is an optical phenomenon that occurs when different wavelengths (colors) of light are refracted by a lens or optical system, leading to a failure to focus all colors to the same...

Change of sensitivity of the eye leading to changed color perception.

The qualities of color associated with hue and saturation, but not brightness or lightness.

Proportions of standard primaries (tristimulus values) required for a color match; ratios of each tristimulus value of a color to their sum. In the CIE colorimetric system, designated X, Y and Z.

The sensations of hue and saturation, taken together, but not brightness or lightness.

The chemical method of separating compounds dissolved in one phase (usually mobile) through its equilibration with a second phase (usually stationary). The mechanism of separation may involve...

A technique of using dyes during endoscopy to improve tissue differentiation. Dyes such as methylene blue, Toluidine blue and Lugol's solution all have the ability to stain particular types of cells....

A layer between the corona and the photosphere of the sun; its emission is overwhelmed by light emitted by the underlying, denser photosphere.

The photographic recording of an action by taking a series of still pictures at regular intervals throughout the action.

CID, or charge injection device, camera refers to a type of imaging device that utilizes a specific kind of solid-state image sensor technology. CID cameras are capable of capturing images in a...

Commission Internationale de l'Eclairage, the international commission on illumination.

Spectral power distribution representing a standard source of illumination, which may be real or hypothetical.

Hypothetical observer having standard color vision as described by standard color-matching properties.

Standard light source representative of the quality of specified natural or artificial illumination.

A camera capable of making successive exposures on a continuous film driven by accurately spaced sprocket holes (a motion picture camera).

The application of a cine camera in recording the images on a fluorescent screen. When x-rays are used to produce the screen images, this process is referred to as cine-radiography.

The technique of making motion pictures.

Cinematography performed with the use of a microscope to film the actions of microscopic specimens.

The photographic filming of the action of x-ray images recorded on a fluorescent screen by means of large lens apertures and highly sensitive filters.

An optical instrument used to track and image a test vehicle (target) throughout its flight. The cinesextant frequently includes multiple devices such as high-speed video and film cameras as well as...

The image of a point source that appears as a circle of finite diameter because of defocusing or the aberrations inherent in an optical system.

Best point of focus for an image in a beam of light at the smallest cross section of the beam.

Circular dichroism (CD) is a spectroscopic technique used to study the structural characteristics of chiral (asymmetric) molecules, particularly biomolecules like proteins, nucleic acids, and certain...

Scanning characterized by the generation of a plane or right circular cone with a vertex angle of about 180° by the direction of maximum radiation.

An optical interference coating, vacuum-deposited on a circular substrate, whose transmission characteristics may be varied by physical rotation.

Circular-ranging optical coherence tomography (CR-OCT) is a specialized imaging technique used in medical diagnostics and research to obtain high-resolution cross-sectional images of biological...

A passive device, having three or more ports, in which input light from one port is coupled only to the next sequential port in a given direction and is prevented from traveling in any other...

For a laser, the maximum exposure time that the laser design allows; 0.25 seconds for a Class 2 laser.

The desensitization of the first photographic exposure after it has been subjected to high-intensity radiation.

In optics, degreasers or ultrasonic arrangements used for removing pitch, cement or polishing material from lenses during manufacture. It also may refer to manual cleaning devices used immediately...

An area in which airborne particulates can be monitored and controlled so that given size particles do not exceed a specified concentration, thereby eliminating potential dysfunctions in gyroscopes,...

In a visual optical system, the axial distance from the last mechanical surface of the eyepiece to the exit pupil.

Denoting a finished circular edge. A decentered lens is adjusted on a centering chuck so that its image runs true, and the lens is then edged. A circular edge is one that has been cleared out....

Also called shining. Grinding and polishing one surface of a blank to permit a more thorough examination for quality.

Naturally occurring planes in crystalline substances that provide easy points for separation.

The application of photography, with the exception of radiography, to obtain pictures of parts or the whole of a patient to make a diagnosis.