A Nicol prism is a classic optical component that splits unpolarized light into two orthogonal polarization states and removes one of them. It consists of a rhombohedral calcite crystal cut at a specific angle and joined back together with Canada balsam. The ordinary ray undergoes total internal reflection at the cement interface and is absorbed by the housing, while the extraordinary ray passes through to provide highly polarized output.
Heard on the job
We replaced the old Nicol prism in the polarimeter with a Glan-Thompson to get better transmission in the UV.
Insider tip
While historically important, Nicol prisms are rarely used in laser labs because their angled faces cause the beam to walk off axis, and the Canada balsam cement cannot handle high optical power.
Do not mix it up with
- Glan-Thompson prism: Both are calcite polarizers, but the Glan-Thompson has entrance faces perpendicular to the beam axis, while the Nicol prism has angled faces that cause slight beam displacement.