Extinction ratios of reverse Rochon prisms

In order to study the extinction ratio of a reverse Rochon prism, extinction ratios of forward direction and reverse direction of a Rochon prism were studied by analyzing photoelastic effect in the prism cement. The reason for the declining of extinction ratio when parallel laser beam passing a Rochon prism backward was studied both in theory and by experiment. The result shows that the extinction ratio is 1.14×10^-5 when parallel laser beam passes through a Rochon prism forward, and extinction ratio is 2.93×10^-3 when beam passes through the prism backward. Extinction ratio is 5.72×10^-5 when beam backward with a λ/4 wave plate. When collimation beam passes through a Rochon prism backward, the extinction ratio of the beam whose propagation direction does not change is decreased because of photoelastic effect in the cementing layer. The experiment verifies the correctness of the theory. The research can provide necessary reference for the designing and the correct using of Rochon prisms.