Polarization Rotation with Totally Internally Reflecting Right Angle Prisms

Matthew Cheyne

Advisor: Dr. Enrique J. Galvez, Colgate University

Abstract

We have designed a pure optical polarization rotator, which rotates the plane of polarization of an incident, linearly polarized light beam. This rotation is due to the phenomenon known as geometric phase, which arises when a beam of light travels through a three dimensional topological path. The device is based on the double-porro prism system such as that found in binoculars. It consists of two right angle prisms with their hypotenuses facing each other, oriented at some angle with respect to each other. One of the prisms rotates changing the geometric phase, and therefore varying the angle of polarization. The prisms have thin film optical coatings deposited on their reflecting surfaces that are used to correct a phase difference between the s and p components of the polarized light that is introduced upon total internal reflection. We have designed two sets of right angle reflecting prisms, one with a single coating on a heavy flint glass, and a second one with two thin film coatings on BK7 glass.