Question

With diagram, give construction of Nicol prism.

Answer 1

Nicol prism is constructed from the calcite crystal PQRS having length three times of its width.

Its end Faces PQ and RS are cut such that the angles in the principle section become 68 and 112 degree in place of &1 and 109 degree.

The crystal is then cut diagonally into two parts.

The surfaces of these parts are grounded to make a optically flat and then are polished.

That is the polished surfaces are connected together with a special cement known as the  Canada Basalm.