Definition of maser in English:



  • A device using the stimulated emission of radiation by excited atoms to amplify or generate coherent monochromatic electromagnetic radiation in the microwave range.

    • ‘Instead of emitting visible light, a maser generates a beam of pure microwave energy - electromagnetic waves intermediate in length between infrared and radar.’
    • ‘There are of course lasers with wavelengths in the infrared, masers that emit coherent microwaves, and even x-ray lasers.’
    • ‘Natural astronomical masers - the analog of laser emission at microwave wavelengths - are one class of coherent sources, but these emit in specific wavelengths.’
    • ‘The complex maser rays and laser concentrate the incredible power of light into rays of various useful strengths: from rays so sensitive you can perform microscopic surgery with them, to brute rays that can pierce through a wall of steel.’
    • ‘Instead of emitting light, like a laser, the maser emits microwave energy at a specific frequency, which produces a very specific ticking.’


1950s: acronym from microwave amplification by the stimulated emission of radiation.