Photonics Dictionary: G

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 laser system consisting of a planar PN junction within a single crystal of gallium arsenide. The pair of parallel, semireflective end faces produces a Fabry-Perot resonant cavity, whereas the other...

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 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...

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...

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.

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...

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...

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...

The area of optics in which the propagation of light is described by geometrical lines (or rays) governed by Fermat's Principle. Geometrical optics is useful as long as the objects in which the light...

Germanium crystal refers to a crystalline form of the element germanium (Ge), which is a metalloid and semiconductor commonly used in various electronic and optical applications. Germanium crystals...

Germicidal ultraviolet (GUV) refers to a specific range of UV radiation that has disinfectant properties capable of killing or inactivating microorganisms, including bacteria, viruses, and fungi. The...

A prefix that is used to represent 109 or 1,000,000,000 in the SI system.

GigE, short for gigabit Ethernet, refers to a standard for high-speed Ethernet communication, capable of transmitting data at rates of up to 1 gigabit per second (Gbps), or 1000 megabits per second...

A furnace, generally electrically heated, with a control system capable of following a cam by which the temperature can be made to go through a definite cycle over a period of days, or even weeks, if...

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...

Unit of mass in the SI system.

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...

A grating beamsplitter is an optical device that utilizes the principles of diffraction to split a beam of light into multiple beams, often redirecting them at specific angles. It is based on the...

A specific, right-angle prism having a transmission grating replicated on its hypotenuse face and used in applications requiring a system that can produce in-line viewing for one wavelength.

In image processing, the range of available gray levels. In an 8-bit system, the gray scale contains values from 0 to 255.

A GRIN (gradient index) lens is a type of optical lens that utilizes a gradient in refractive index across its volume rather than having a uniform refractive index like conventional lenses. This...

The process in the manufacture of an optical system that gives it the required geometric shape.

Also known as ground level. The lowest energy level of an atom or atomic system. A material in the ground state is not capable of emitting optical radiation. All other states are called excited...

A term variously applied to remote sensing techniques that essentially refers to all parametric conditions that influence the sensor system; includes the quantitative reality that the sensor sees and...

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

An optical device that permits the alignment of a gun, cannon or rocket launcher system with its target.

A gyroscope is a mechanical device consisting of a spinning disk or wheel mounted on a spinning axis in such a way that its orientation remains fixed regardless of any movement of its mounting...