Rochon棱镜反向使用消光比

为了研究Rochon棱镜反向使用消光比特性，采用分析棱镜胶合剂中光弹效应的方法，对Rochon棱镜正、反向使用时消光比进行了分析，并设计了实验，从理论和实验上对平行光反向通过Rochon棱镜时消光比下降的原因进行了研究。结果表明，当平行光正向通过Rochon棱镜时，消光比为1.14×10-5；反向通过时，消光比为2.93×10-3；反向通过加上λ/4波片后，消光比为5.72×10-5；准直光束反向通过Rochon棱镜时，由于胶合剂中的光弹效应的存在，使得传播方向不改变的一束光的消光比下降，验证了理论分析的正确性。该结果可为Rochon棱镜的设计制作和正确使用提供必要的参考。

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.