Photonics Marketplace

Suppliers Products

Handbook Institutions Dictionary

Show Filters

Hide Filters

Type

DefinitionsAbbreviations/Acronyms

Browse by Letter

Hamamatsu Corp. - Mid-Infrared LED 11/24 HP

8,726 terms

Photonics Dictionary

gallium arsenide phosphide

Gallium arsenide phosphide (GaAsP) is a semiconductor alloy composed of gallium (Ga), arsenic (As), and phosphorus (P). It is commonly used in the fabrication of optoelectronic devices, particularly...

gallium arsenide

Gallium arsenide (GaAs) is a compound semiconductor material composed of gallium (Ga) and arsenic (As). It belongs to the III-V group of semiconductors and has a zincblende crystal structure. GaAs is...

gallium nitride

Gallium nitride (GaN) is a compound made up of gallium (Ga) and nitrogen (N). It is a wide-bandgap semiconductor material that exhibits unique electrical and optical properties. Gallium nitride is...

galvanoluminescence

The emission of radiant energy produced by the passage of an electrical current through an appropriate electrolyte in which an electrode, made of certain metals such as aluminum or tantalum, has been...

galvanometer mirror

A small mirror, sometimes plane and sometimes concave, attached to the rotating coil of a galvanometer to cause a spot of light to move along a scale.

galvanometer

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....

galvanometric scanner

A galvanometric scanner, also known as a galvanometer scanner or galvo scanner, is a type of optical scanning device used to rapidly and precisely direct a laser beam or other light source to...

galvo-directing mirrors

A system of mirrors that can be used to direct light from a single laser source into any one of a number of separate optical fibers.

gamma

A numerical value representing the degree of contrast in a television picture: the exponent of the power law used to approximate the curve of output magnitude vs. input magnitude over the region of...

gamma camera

A camera used in scintillation recording to make a visible record of the distribution and relative concentration of radioactive tracer elements in a sample that is undergoing scanning.

gamma correction

Modification of a system to provide for a linear transfer characteristic from an input to an output device. A circuit for this purpose is built into a television camera to compensate for display tube...

gamma radiography

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

gamma ray

The spontaneous emittance of electromagnetic radiation by the nucleus of certain radioactive elements during their quantum transition between two energy levels. The radiation emitted has a wavelength...

gamma-ray spectrometer

An instrument used to detect and measure the energy distribution of gamma rays. It has been used to chart the radioactivity at the lunar surface.

GaN

gallium nitride

GaN distributed feedback lasers

GaN (gallium nitride) distributed feedback (DFB) lasers refer to a specific type of semiconductor laser based on Gallium Nitride materials and designed with a distributed feedback structure. These...

GaN-based LEDs

Gallium nitride-based light-emitting diodes (GaN-based LEDs) are semiconductor devices that emit light when an electric current passes through them. These LEDs are constructed using gallium nitride...

gap loss

The optical power loss caused by a space between axially aligned fibers.

gas current

The positive ion current created in an electron tube as a result of the collisions between electrons and residual gas molecules.

gas discharge

The conduction of electricity in a gas as a result of the ions generated by collisions between electrons and gas molecules.

gas discharge display

A display device that contains an inert gas that gives off orange light when a high voltage is applied to ionize the gas.

gas discharge laser -> gas laser

One of the first lasers to find practical application. Generally, the pumping mechanism is an electric discharge, although some high-power forms employ chemical reaction or gas compression and...

gas filter correlation

A technique for measuring the concentration of any gases. Identical infrared beams are alternately chopped, one passing through a reference cell and the other passing through a cell with the gas...

gas focusing -> ionic focusing

Also known as gas focusing. The introduction of an inert gas into a cathode-ray tube for the concentration of the electron beam. The gas molecules are ionized by the electrons, producing a core of...

gas laser

One of the first lasers to find practical application. Generally, the pumping mechanism is an electric discharge, although some high-power forms employ chemical reaction or gas compression and...

gas magnification

The increase in current of a phototube as a result of the gas in the tube becoming ionized.

gas photocell

A photoemissive cell having an inert gas added to its envelope. Subsequent ionization of the gas increases the responsivity of the photocell.

gas phototube

A phototube having increased response due to the addition of a quantity of gas.

gas tube

An electron tube whose current flow is affected by the pressure on the gas or vapor contained in the tube.

gas-transport laser

A gas laser wherein the gas mixture is not exhausted into the atmosphere but is continually recycled. It is excited in the active region, cooled and re-excited. The GTL requires no constant gas...

GASP

graphic applications subroutine package

gastroscope

An optical instrument designed for the visual examination of the inside of the stomach.

gateable

In detectors, the ability to switch on and off electronically, thus producing the effect of a mechanical shutter.

gated image tube

An intensified charge-coupled device that uses a large negative charge at the grid to switch off the flow of electrons at periodic intervals in order to provide a clearer output image when adverse...

gated integrator -> boxcar averager

An instrument for detecting and analyzing repetitive signals. Using a fixed time delay or "gate," the input signal is sampled numerous times and averaged to increase the ratio of the...

gated pulse

A discontinuous burst of laser light generated by timing or "gating'' a continuous-wave laser.

gatling gun laser -> multiple laser sequence

Also known as gatling gun laser. A system that has an array of lasers sharing a common central axis on a rotating Fabry plate to achieve increased laser firing rates by sequential Q-switching.

GATT

general agreement on tariffs and trade

Gauss lens

A telescope objective with excellent spherochromatic correction, consisting of a meniscus crown and a meniscus flint, both convex to the long conjugate.

Gauss points -> cardinal points

Focal, nodal or principal points of a lens. If the respective distances of the object and image are measured from the cardinal points, all thin-lens equations are applicable to thick lenses.

Gaussian beam

A beam of light whose electrical field amplitude distribution is Gaussian. When such a beam is circular in cross section, the amplitude is E(r) = E(0) exp [-(r/w)2], where r is the distance from beam...

Gaussian beam optics

The area of optics that deals with the propagation of Gaussian laser beams in free space, or any general medium - i.e. lenses- under the paraxial (small divergence angle) approximations. Gaussian...

Gaussian optics

1. That branch of optics that illustrates the theory in which q is substituted for sin q in Snell's law. Effective results are achieved if the aperture and field angle are made very small. The...

Gaussian profile

An intensity distribution (intensity as a function of radial distance from the beam center) which is given by the Gaussian function: where: I0 is the intensity at the beam center r is the radial...

Gaussian pulse

A pulse that has the waveform of a Gaussian distribution.

gauze technique

The masking of all openings of an optical transform -- except the hole at the symmetrical center -- with a thin wire gauze to attain a more precise image.

gigabits

gigabytes

Gb/s

gigabits per second

GbE

gigabit Ethernet

Photonics Dictionary

Need Help?