Photonics Dictionary: G

In image processing, machine vision and television, discrete brightness values quantized for a group of pixels. They can range from white, through various shades of gray, to black.

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...

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...

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...

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...

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...

An acronym of gamma ray amplification by stimulated emission of radiation. It is a gamma ray laser that operates between energy levels established by metastable isomeric transitions in the nucleus.

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

An image consisting of an array of pixels that can have more than two values (black and white). Typically, up to 16 levels are possible per pixel.

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...