Elliptic Polarimeter for the Student Laboratory: “Specimens” of Elliptically Polarized Light

The elliptic polarimeter here described for use in the advanced undergraduate laboratory is simple and inexpensive, yet its precision approaches that of a research instrument. Experiments with it are simplified by providing the student with “specimens” of elliptically polarized light made by binding together with suitable orientation a Polaroid and a birefringent plate of approximately quarter-wave retardation. Precision is attained by means of an improved form of analyzer. The errors encountered with a compensator plate that does not produce exactly quarter-wave retardation are analyzed and a method for taking data is developed which reduces the final errors to small second-order terms.