Photonics Dictionary

A type of internal photonic connection in an integrated circuit in which a holographic grating is used to focus light at points on a silicon chip, maximizing the speed of signal propagation.

The frequency domain is a concept used in signal processing and analysis to represent signals and data in terms of their frequency components. In contrast to the time domain, where signals are...

A technique used in holography that involves the mixing of lasers of different wavelengths to produce a beam of shorter wavelength.

The full width at half maximum (FWHM) is a measure used in various fields, particularly in spectroscopy, signal processing, and imaging, to characterize the width or extent of a distribution, peak,...

Fused quartz and silica are closely related materials, both composed primarily of silicon dioxide (SiO2), but they are produced through different manufacturing processes and have distinct properties...

A GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic spectrum. It is composed of layers of gallium, aluminum, and arsenic, hence...

A galvanometer is an instrument used for detecting and measuring small electric currents. It typically consists of a coil of wire suspended in a magnetic field, with a pointer attached to the coil....

Radiography using the emission of gamma rays to form an image of the structure penetrated by the radiation.

An early form of photographic media consisting of glass plates coated with an emulsion.

A spectrograph having glass as its refracting component and used in cases where speed and high dispersion are not required. The glass material has a range of about 3700 to 8000 Å.

The Golgi staining technique (also called the black reaction) makes it possible to look at the nervous system by rendering neurons visible under light microscopy. After a long process involving...

The graphed curve illustrating the directional reflectance of a sample for different angles of collection.

An electron tube having two electron guns, one on each side of the storage medium, to encode the information onto the medium, and to read and simultaneously erase the electrostatic encoding.

Graphene is a two-dimensional allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal lattice pattern. It is the basic building block of other carbon-based materials...

The soft x-rays used in the industrial radiography of materials having too small a range of densities to produce an image with normal x-rays.

A factor derived by equating the incident light on the subject to the required incident light for suitable photography. The lamp-subject-distance then is multiplied by the aperture and solved in...

A camera accurately aligned to a weapons system to provide a photographic record of system performance.

1. In a cathode-ray tube, the glow surrounding a bright spot that appears on the fluorescent screen as the result of the screen's light being reflected by the front and rear surfaces of the tube's...

1. The faintly hued ring that is seen to surround a light source viewed through fog or light clouds. The size of scattering particles determines the size of the ring. 2. The ring surrounding a...

A device small enough to be held in a hand that uses a magnifying lens and a translucent back to permit the viewing of photographic transparencies.

An instrument designed to calculate the amplitude and phase of the different harmonic elements of a radiation wave utilizing a graph of the wave.

A test for spherical aberration, coma or astigmatism in which incident rays from a point source are isolated by small holes in a metal disc located close to the lens or mirror under test....

A filter, used in photography, that absorbs the ultraviolet and extreme blue violet radiation scattered by atmospheric haze.

An instrument designed to record the duration and intensity of solar radiation.

A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates based on the principle of stimulated emission of photons from excited helium...

The decrease in effect in developable density on a photographic plate formed by a second exposure to radiation having a longer wavelength, usually red or infrared.

A term used to describe a photograph, film or television picture where the values for black and white areas are at or near their limits, thereby giving the maximum degree of difference between them.

Extensive data storage in the form of bits, with the use of high-resolution photographic materials and optics, and generally a laser.

A high-sensitivity camera is a type of camera designed to perform well in low light conditions, capturing clear and detailed images with minimal noise. These cameras typically feature advanced sensor...

The holographic recording of sequences of high-speed phenomena. With a multiple beam laser, multiple holograms that depict rapid events can be formed on a single medium.

Photography involving the recording of events that occur too fast to be perceived by the human eye or recorded by conventional photographic techniques. See high-speed movie camera; high-speed...

A method of producing x-ray exposures as short as 0.03 µs; the primary application is in ballistic radiography.

A shutter actuated by means other than mechanical springs for timings on the order of nanoseconds. The shutter is used in the photography of rapid moving objects or events.

A fish-eye lens designed to photograph cloud formations over the entire visible sky.

A graphic representation of a distribution function such as frequency by means of rectangles whose widths represent the intervals into which the observed values' range is divided and whose heights...

Techniques used in biology to produce microradiographs of cells, tissues or small organisms.

A camera system used to form a high-precision hologram of the subject on a photographic plate. It contains a high-power pulsed laser as the illuminating source.