American physicist who, in 1960, invented the laser. He used the three-level principle worked out by Bloembergen. He constructed a ruby cylinder with the ends polished flat and parallel and silvered. Energy was fed in using a flash lamp. The output was a monochromatic coherent beam of radiation. By way of analogy with the maser, Maiman's device was given the acronym laser, standing for "light amplification by stimulated emission of radiation."