Photonics Dictionary

3D Laser Triangulation - A technology that allows sensors to probe the surroundings. Laser triangulation systems have an ideal operating point, or the standoff distance, where its reflected spot is...

A measuring device that uses a light-sensitive cell or detector to determine the amount of light transmitted by a substance.

Component that is externally controlled via electronic or photon signal.

Agri-photonics refers to the application of photonics technologies in agriculture. Photonics involves the generation, manipulation, and detection of light and other forms of radiant energy whose...

An APD detector, or avalanche photodiode detector, is a type of photodetector used to detect light or optical signals by converting incoming photons into electrical current. It operates based on the...

An atomic absorption spectrometer (AAS) is an analytical instrument used to determine the concentration of specific chemical elements in a sample by measuring the absorption of light at...

A receiver for optical communications systems consisting of a symmetric binary, pulse-code-modulated transmitter, a log-normal channel and an array of independent photocounting detectors that yield...

A ball lens is a small, spherical optical component typically made of glass or other transparent materials. It is characterized by its spherical shape, with both its front and back surfaces forming...

Beam profiling is a technique used to characterize and analyze the spatial intensity distribution of a laser beam. It involves measuring and visualizing how the optical power or intensity is...

Signal used in optical transmission systems to generate currents in a detector that are decoded with reference to a specified threshold.

A detector's ability to sense an object on the opposite side of a thin but opaque barrier such as cardboard.

A light-tight box that receives light from an object or scene and focuses it to form an image on a light-sensitive material or a detector. The camera generally contains a lens of variable aperture...

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...

A system that generally uses a photodetector to decode punched cards for information, or for input to a computer, by sensing the light transmitted through the punched holes.

In an interferogram, an intense portion of the recording that corresponds in size to the amount of infrared radiation incident on the detector.

A photoemissive detector sensitive to wavelengths up to 1 µm. It has one sharp maximum of sensitivity at 350 nm and a broad maximum at 800 nm.

Chalcogenide refers to a class of compounds containing elements from group 16 of the periodic table, which includes sulfur (S), selenium (Se), and tellurium (Te). These elements are known as...

A photoelectric detector consisting of a glass tube internally coated with a low conductance material. Voltage applied along the tube causes photoemission from the photocathode at the end of the tube...

A light-sensitive detector having a chemical compound that reacts when exposed to light. It is used in photochemistry and relies on the chemical reaction to determine the amount of incident radiation.

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 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...

A cryogenically cooled component incorporated into the Dewar of an infrared detector assembly to maintain the sensing elements at the proper temperature (77 K or colder).

A microscope design that involves apertures inserted in conjugate plane positions inside the microscope, with one aperture in front of the illumination source and the other at the focal position in...

An infrared detector that achieves a specified sensitivity through the application of certain cryogenic temperatures.

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...

1. In detector technology, the long wavelength at which detector response falls to a set percentage (usually 20 or 50 percent). 2. In fiber optics, the shortest wavelength at which a fiber transmits...

A value used to designate the relative sensitivity of a detector. The higher the D* value, the better the detector.

The interval between direction of signal to a light-emitting diode and attainment of 10 percent output current in the photodetector.

A measure of the sensitivity of a detector; the reciprocal of noise equivalent power (NEP). See D*.

1. A device designed to convert the energy of incident radiation into another form for the determination of the presence of the radiation. The device may function by electrical, photographic or...

A detector array refers to a collection of individual detector elements arranged in a two-dimensional grid or matrix format. Each element within the array is capable of detecting electromagnetic...

A detector-Dewar assembly typically refers to a combination of a detector and a Dewar flask used in scientific instruments, particularly in the field of infrared spectroscopy or other applications...

A type of pyroelectric detector with favorable qualities of linearity, sensitivity and spectral responsivity used in FTIR detectors.

A dichroic mirror, also known as a dichroic beamsplitter or interference filter beamsplitter, is an optical device that selectively reflects or transmits light based on its wavelength. Dichroic...

Diffuse reflectance spectroscopy (DRS) is a nondestructive analytical technique used to investigate the optical properties of materials, particularly in the field of spectroscopy. Unlike traditional...

An imaging process, similar to specific Doppler mapping radar techniques, that utilizes a laser, an optical imaging system, and a line array of photodetectors and spectrum analyzers. The laser...

A spectrophotometer in which the beam emitted by the radiation source is split into beams that travel through the sample and a reference cell and are subsequently recombined to fall on the detector....

A type of mosaic detector array that combines features of scanning and staring sensors by using a small rapid scanning motion (see saccadic motion) over a few pixels at a time.

A device that detects radiation by utilizing the influence of light in forming an electrical signal. It may be a phototube; a photoconductive, photovoltaic or photojunction cell; a phototransistor;...

A factor, F, indicating the increase in shot noise in an avalanche photodiode as compared with the ideal multiplier, which is noiseless. The noise, which results from variations in avalanche gains,...

A photodetector composed of a semiconductor material whose responsive properties can be altered by the addition of impurities to the basic material. Copper- and mercury-doped germanium are both...

Measurement of the interval during which a photodetector's signal and output current drops from 90 to 10 percent.

The signal-to-noise ratio (SNR) obtained with a Fourier transform spectrometer when detector noise prevails, which exceeds the SNR of a scanning spectrometer in the same time by a factor proportional...

A fiber optic gyroscope (FOG) is a type of gyroscope that uses the interference of light waves to detect changes in orientation or rotation. It operates based on the principle of the Sagnac effect,...