Photonics Dictionary: C

A C-mount lens refers to a specific type of lens commonly used in machine vision, surveillance, microscopy, and other imaging applications. The "C-mount" designation refers to the standard interface...

An oil immersion condenser used to permit only light that has been diffracted or dispersed by a microscope specimen to enter the microscope. It is used in dark-field microscopy.

A lens, one surface being a cartesian oval, that produces an aplanatic condition.

A two-mirror lens design used in astronomical telescopes, the primary being a parabola, the secondary a smaller hyperbola. The image formed is free of spherical aberration and color and is located...

Cathode radiant sensitivity refers to the ability of a photocathode to convert incident radiant energy, typically in the form of light, into an electrical signal. Photocathodes are components used in...

A high-quality, narrow-angle lens of high aperture designed for low magnification in the recording of cathode-ray tube images.

A CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images into electronic signals. It is a key component in digital cameras, camcorders,...

A lens system in which the centers of curvature of all surfaces fall on a common axis.

The number of channels per unit bandwidth handled by a single optical fiber.

See charge-coupled device; charge-injection device.

In a charge-coupled device, the percentage of each charge packet that is carried over to the next stage of the transport shift register.

Chemical sensing refers to the detection and measurement of specific chemical compounds or substances in various environments or samples. It involves the use of sensors or analytical techniques to...

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.

A CMOS image sensor, short for complementary metal-oxide-semiconductor image sensor, is a type of semiconductor device used to capture visual information and convert it into electrical signals for...

A numerical representation of the rate at which a material will exhibit dimensional changes as a direct result of changes in temperature.

A fiber optic communications system that works on the principles of homodyning or heterodyning. The transmitting laser produces an optical wave that is modulated in amplitude, phase or frequency by...

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

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...

An instrument providing a continuous measure of color.

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

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 device used to project a reference spectrum next to a spectrum to be analyzed to provide visual comparison.

A corner reflector that provides an increase in the range of angles over which it may be used.

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.

Also known as clear glass or clear filter. The clear glass plate is used to simulate a filter, in converging or diverging light, to maintain focus.

An optical element that measures the phase difference between two components of elliptically polarized light to correct for mechanical or optical displacement.

A lens made up of a number of lens elements arranged into two or more groups.

A lens composed of two or more separate elements of optical glass that may or may not be cemented together. The surfaces of the elements are shaped to reduce or eliminate the aberrations inherent in...

A lens with one concave surface and one convex surface; synonymous with meniscus.

A lens having surfaces whose centers of curvature coincide.

A single positive lens or group of lenses used in a projection system to collect light from a source and cause it to illuminate evenly the object to be projected.

A lens with a surface that is a cone instead of the usual sphere.

A device used to determine the location and attitude with respect to the Earth of orbiting spacecraft by detecting the difference in thermal radiance between the Earth's horizon and space.

The principle that states that optical instrumentation cannot increase the radiance of a source; the radiance of an image cannot exceed that of the object.

That property of certain optical devices, e.g., a penta prism, that maintains the angular relationship between the entering and the emerging rays traversing the system regardless of the orientation...

Method of disk rotation used for optical disk drives, in which the spindle motor decreases the speed of the disk's rotation as the head moves from the inner tracks to the outer, so that the radial...

A device used in broadcast CCD cameras to improve definition in heavily saturated colors by band-limiting the color difference signals after gamma correction.

Technique that uses high-pass filtering to reduce the local average to zero for all regions of the picture and then applies a gain factor equal to the reciprocal of the local standard deviation to...

Reciprocal of the dispersive power of an optical material. See Abbe constant.