optical maser vs laser

optical maser and laser both are nouns.

Word	Noun	Adjective	Verb	Adverb
optical maser	Yes	No	No	No
laser	Yes	No	No	No

As nouns, optical maser and laser are synonyms defined as:

optical maser and laser: an acronym for light amplification by stimulated emission of radiation; an optical device that produces an intense monochromatic beam of coherent light

optical maser (noun)	laser (noun)
an acronym for light amplification by stimulated emission of radiation; an optical device that produces an intense monochromatic beam of coherent light	an acronym for light amplification by stimulated emission of radiation; an optical device that produces an intense monochromatic beam of coherent light