Nicol prism

A Nicol prism is an optical device used to produce and analyze polarized light, which vibrates in a specific direction. Made from calcite crystal split into two parts, it filters light so only waves aligned in one plane pass through. When unpolarized light (vibrating in multiple directions) enters, the prism allows only the polarized component to emerge, creating a beam of light with a single vibration direction. This technique is helpful in studying materials' properties and in scientific experiments where controlling light vibrations is important.