polariscope vs optical device

polariscope and optical device both are nouns.

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

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

polariscope: 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

polariscope (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