polarimeter vs optical device

polarimeter and optical device both are nouns.

Word	Noun	Adjective	Verb	Adverb
polarimeter	Yes	No	No	No
optical device	Yes	No	No	No

As nouns, optical device is a hypernym of polarimeter; that is, optical device is a word with a broader meaning than polarimeter:

polarimeter: an optical device used to measure the rotation of the plane of vibration of polarized light
optical device: a device for producing or controlling light

polarimeter (noun)	optical device (noun)
an optical device used to measure the rotation of the plane of vibration of polarized light	a device for producing or controlling light