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...

Also known as amplification. 1. The increase in a signal that is transmitted from one point to another through an amplifier. A material that exhibits gain rather than absorption, at certain...

Gain-switching is a technique used in lasers to generate short pulses of light by modulating the gain of the laser medium. This method is distinct from Q-switching and mode-locking, two other common...

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...

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...

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...

Trade name referring to an instrument that determines surface distances by measuring the length of time it takes for a modulated lightwave to reach a mirror and be reflected to its point of origin.

The position and shape of the image of a point source, as predicted by geometric optics alone. The geometric image is to be differentiated from the diffraction image, which is determined from...

The superposition of satellite or aerial images with a map in order to process and remove distortion. Uses reference points from map to align and apply information.

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 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...

In an image, the orientation and magnitude of the rate of change in intensity at any point.

In a multicrystalline material, the meeting point between crystallites.