what is nicole prism ?

A Nicol prism is a type of polarizer, an optical device used to produce a polarized beam of light from an unpolarized beam. It is made in such a way that it eliminates one of the rays by Total Internal Reflection i.e, the O-ray is eliminated and only the E-ray is transmitted through the prism.

The Nicol prism is made up from two prisms of calcitecemented with Canada balsam . Theordinary ray can be caused to totally reflect off the prism boundary, leaving only the extraordinary ray.