• Microwave Amplification by Stimulated Emission of radiation – the microwave version of a laser. Celestial masers of great power are observed by radio astronomers and are the result of microwaves being trapped and amplified in gas clouds.


  • Abbreviation of microwave amplification by stimulated emission of radiation. A device whose operation is similar to that of a laser, and which is utilized to amplify or generate coherent microwave radiation. Examples include gas and solid-state masers. Used, for instance, in communications, radio astronomy, radars, and as time and frequency standards.
  • synonymmicrowave amplification by stimulated emission of radiation