Optical maser and Optical device

Optical maser noun - An acronym for light amplification by stimulated emission of radiation; an optical device that produces an intense monochromatic beam of coherent light.

Optical device and optical maser are semantically related. In some cases you can use "Optical device" instead a noun phrase "Optical maser".

Optical device noun - A device for producing or controlling light.

Optical maser and optical device are semantically related. Sometimes you can replace phrase "Optical maser" with "Optical device", this phrases are similar.