General English


  • Lasers are made by gathering light energy in a special ‘cavity’ and releasing it in bursts of the same wavelength and with every wave in phase, in other words in step rather than randomly distributed. Laser light has many uses – e.g., it can pack enough power to be used to reflect from mirrors in orbit or on the surface of the Moon (Laser Ranging). In addition, astronomers have found weak natural lasers acting in space where gas clouds can form a natural cavity. The atmospheres of Jupiter and Mars are known to house such lasers as are the gasses surrounding new stars in Orion and Cygnus.


  • noun a device that produces coherent light of a single wavelength in a narrow beam, by exciting a material so that it emits photons of light.


  • An acronym for light amplification by stimulated emission of radiation, a device that amplifies radiation in the visible or infrared parts of the spectrum.


  • A device whose output is a coherent, monochromatic, and essentially non-divergent beam of light in the visible, infrared, ultraviolet, or X-ray region of the electromagnetic spectrum. The input power of a laser is utilized to excite the electrons of atoms, molecules, or ions to higher energy levels, and these particles are made to radiate in phase within a cavity with mirrors at the ends. Any of various materials or mediums may be stimulated through electrical, chemical, or other means into emitting laser radiation, including crystals, dyes, gases, or liquids. The coherent light produced may be continuous, or it may occur in pulses. Lasers have many applications, including their uses in communications, surgery, cutting, drilling, heating, holography, distance measurement, printing, spectroscopy, and disc storage and retrieval. Also called optical maser.
  • synonymlight amplification by stimulated emission of radiation


  • noun an instrument which produces a highly concentrated beam of light which can be used to cut or attach tissue, as in operations for a detached retina

General Science

  • abbreviation forlight amplification by stimulated emission of radiation