Wollaston Prism Polarizer

A Wollaston prism polarizer consists of two right angle prisms made of a uniaxial crystal such as calcite, which is commonly used for Wollaston prisms. The two pieces of uniaxial crystal are oriented such that the crystal axes are perpendicular to each other. Using the geometry shown in the figure below, horizontally polarized light propagates in the extraordinary index of refraction (ne) in the first section and is refracted into the ordinary index of refraction (no) in the second section. Vertically polarized light undergoes the opposite refraction and the two polarization states are thus separated. This knowledge base article describes a script, WollastonCreator.frs, that creates a Wollaston prism based on user specifications entered into a Basic dialog. It allows for different dimensions in all three directions. The FRED file, wollatsonPrismPolarizers.frd, includes two Wollaston prisms generated using the creator script—one based on a ThorLabs model and another on an Edmund Optics model. The Wollaston creator script and the birefringent material creator script from a previous knowledge base post are included as Embedded Scripts for convenience. The birefringent material creator may come in useful for defining birefringent materials for the Wollaston prism polarizer.

wollaston

Wollaston prism polarizer with crystal axes labeled as black arrows. Horizontally (x) polarized light is refracted up and vertically (y) polarized light is refracted down (assuming a negative uniaxial crystal with no > ne).

 WollastonPrismPolarizer.pdf

Download the WollastonCreator.frs FRED script

Download the WollastonPrismPolarizers.frd FRED file