masern.

1955 Sci. News Let. 5 Feb. 83/1 Scientists can, for the first time, generate microwaves of extremely high frequency by tapping directly the energy of molecules, Dr. Charles H. Townes of Columbia University's physics department reported in New York. His device for doing so is known as the ‘maser’.

1955 C. H. Townes et al. in Physical Rev. 15 Aug. 1264/1 The device utilizes a molecular beam in which molecules in the excited state of a microwave transition are selected. Interaction between these excited molecules and a microwave field produces additional radiation and hence amplification by stimulated emission. We call an apparatus utilizing this technique a ‘maser’.

1960 N.Y. Times 8 July 7/6 The Hughes device is an optical maser, or ‘laser’, (the ‘l’ standing for ‘light’).

1974 L. Niven & J. Pournelle Mote in God's Eye (1975) i. iv. 35 It'll use up a significant part of our engine power to produce the maser beam.

1990 Annapolitan July 108/3 Joe Weber became a leading authority on lasers, masers, and general relativity.

1967 Ann. Rev. Astron. & Astrophysics 5 201 Although we cannot yet specify a model for the OH maser, it is of interest to compute order-of-magnitude limits to the OH masses necessary to give the observed gain.

1986 Nature 26 July 270/1 They surveyed the nuclei of 29 nearby galaxies and found four new water-vapour masers.

1992 S. P. Maran Astron. & Astrophysics Encycl. 733/2 There are three main categories of cosmic masers: (i) masers occurring in the immediate surroundings of highly evolved, dying stars (the so-called ‘circumstellar masers’), (ii) masers in the immediate surroundings of recently formed stars (usually, but less precisely, called ‘interstellar masers’), and (iii) ‘megamasers’ discovered in distant, active galaxies.