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 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...

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...

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...

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 device similar to the ordinary spectrophotometer but containing particular modifications to provide for the comparison of two sources.

A photometer for measuring gloss by comparing the specular reflectance to that from a perfect specular reflector.

A lamp in which the ionization of the inert gas contained in it produces a glow in the space close to the negative electrode.

Gram-positive bacteria are a group of bacteria that have a thick cell wall composed primarily of a substance called peptidoglycan. This thick peptidoglycan layer retains a stain called crystal violet...

1. A measure of absorbed dose, equal to the energy imparted by ionizing radiation to a mass of matter corresponding to 1 J per kilogram. 2. A term used to denote an incompletely polished surface that...

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...