Before LASER, there was MASER. MASER is an acronym for Microwaves Amplification by Stimulated Emission of Radiation, whilst the ‘L’ for LASER stands for Light.
MASER was developed during World War 2 by an American Physicist; Charles Townes at Bell Laboratories.
MASERs were modestly useful, for scientific research mainly but not so much for military or industrial applications.
MASER was later developed into LASER by an American Engineer and Physicist, Thomas Maiman in 1960 thus creating the first ruby laser, producing a perfectly straight red laser beam.