maser - technical definition

The maser is a device similar to the laser, but emitting microwave radio waves rather than light. In 1953, Charles H. Townes, James P. Gordon, and Herbert J. Zeiger invented the maser, which earned them the Nobel Prize in Physics in 1964. Research continued into the 1950s, leading to the optical maser, or laser, for which AT&T Bell Telephone Laboratories was awarded a patent in 1960. See also laser.