laser

(LAY-zer) A device that concentrates light into an intense, narrow beam used to cut or destroy tissue. It is used in microsurgery, photodynamic therapy, and for a variety of diagnostic purposes.

An active electron device that converts input power into a very narrow, intense beam of coherent visible or infrared light; the input power excites the atoms of an optical resonator to a higher energy level, and the resonator forces the excited atoms to radiate in phase. Derived from Light Amplification by Stimulated Emission of Radiation and classified from Class I - Class IV according to its potential for causing damage to the eye.

Acronym for light amplification by stimulated emission of radiation. A device that produces a coherent beam of optical radiation by stimulating electronic, ionic, or molecular transitions to higher energy levels so that when they return to lower energy levels they emit energy. Note 1: Laser radiation may be either temporally coherent, spatially coherent, or both. Note 2: The degree of coherence of laser radiation exceeds 0.88.