Photonics Dictionary: C

An instrument providing a continuous measure of color.

Any known value derived from standard analysis that serves as a reference to the accuracy of an instrument or process in determining one or more variables.

An instrument used to measure the change of heat content of a system by measuring microwave power in terms of generated heat.

Calorimetry is a branch of science that involves the measurement of heat flow in physical or chemical processes. It encompasses various techniques and instruments used to quantify heat transfer,...

A portable instrument that uses a four-sided reflecting prism or set of mirrors to create a duplicate image of an object on a horizontal sheet, on which outlines of the subject may be traced by hand.

A forerunner of the modern camera, this instrument had a focusable lens that produced a sharp image on the enclosure opposite the aperture but had no photosensitive material to record it.

An instrument incorporating an infrared detector assembly, used to analyze carbon dioxide gases and in medical applications to monitor air exchange in the lungs of patients on ventilators or under...

An instrument consisting of a high-voltage vacuum tube used to form hard x-rays or high-speed ion beams. By partitioning the tube into separate sections, the total voltage is divided.

A container designed to hold recording material (film, video- and audiotape) so that when it is loaded into a recording instrument, the recording material is threaded simultaneously.

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...

An instrument that detects high-energy charged particles by analysis of the Cerenkov radiation that they emit.

A charge-coupled device (CCD) is a type of electronic image sensor used in various imaging devices, including digital cameras, camcorders, and scientific instruments. It consists of an integrated...

An instrument designed to analyze the optical effects of color.

The ability of the instrument to separate wavelengths that are close together, numerically equal to the ratio of the shorter wavelength to the difference between two wavelengths that can just be...

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...

An instrument for measuring the vertical angle of an object. It usually contains an accurately made protractor, a sensitive level bubble, and a sighting device, such as a small telescope.

A reticle carrying patterns of various forms that can be rotated in an optical beam to cause variations in the intensity of the beam. It also is used in infrared detectors to scan the object field...

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...

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...

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...

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.

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...

Concave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These mirrors are commonly used in optics for various applications, including...

An interferometer formed by two similar concave spherical mirrors arranged with the center of one sphere on the other mirror. In this instrument the field is more concentrated by the axis of the...

An optical instrument, generally a polarizing microscope, that is used to determine the interference figures and optical axis of a sample crystal. Also called a hodoscope.

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.

Convex is an adjective used to describe a surface or shape that curves outward, bulges, or has a rounded and outwardly extending appearance. In the context of geometry or optics, a convex shape is...

An instrument used to measure the coordinates of a point on an object such as a photographic plate.

A corner cube, also known as a corner reflector or retroreflector prism, is a type of optical device used to reflect light or electromagnetic waves back towards their source with minimal deviation in...

Fine lines, wires or threads used in the focal plane of many optical instruments to point out and locate particular objects in the field of view. They were formerly made from a single strand of...

An instrument that is used to detect high-energy particles by the pulse of the current formed when a particle passes through a normally insulating crystal to which a potential difference is applied.

A diode with a semiconducting material, such as germanium or silicon, for one electrode, and a fine wire "whisker'' which lies on the semiconductor, as the other electrode. The low capacitance...

A sudden, brief increase in current or voltage in a circuit that can damage sensitive components and instruments. Preventive measures include slow-starter circuits, filtering and static control.

An instrument designed to measure the proportion of light emitted by a source in the blue region of the spectrum.