Gas Discharge Laser

A laser containing a gaseous lasing medium in a glass tube in which a constant flow of gas replenishes the molecules depleted by the electricity or chemicals used for excitation.

Gas Laser

A type of laser in which the laser action takes place in a gas medium.

Gated Pulse

A discontinuous burst of laser light, made by timing (gating) a continuous wave output - usually in fractions of a second.

Gaussian Curve

Statistical curve showing a peak with normal even distribution on either side. May either be a sharp peak with steep sides, or a blunt peak with shallower sides. Used to show power distribution in a beam. The concept is important in controlling the geometry of the laser impact.


a spectrometer or autocollimator used for measuring prism angles.

Ground State

Lowest energy level of an atom.