一种改进型菲涅尔棱体的设计与分析

通过对光学材料和器件内全反射角的优化设计，提出一种改进型菲涅尔棱体模型，使入射光在器件内以相同的内反射角θ在两种不同玻璃材料和空气构成的界面上发生两次全反射，由反射引起的相位延迟的变化可以相互补偿，从而设计出对入射角不敏感的相位延迟器.计算表明，入射角变化±2°时，该相位延迟偏差不超过0.36°，且保持了原型菲涅尔棱体正入射和正出射的优点，大大方便了使用. 关键词： 相位 全内反射角 折射率

Design of an improved Fresnel prism

Based on the optimization of the optical material and internal reflection angle, we designed a model of improved Fresnel prism that is insensitive to the angle of incidence. In this device, the incident light is reflected twice at the same internal reflection angle on the interface between two kinds of glass and the air. So the changes of retardation caused by reflection can compensate each other. The calculation shows that the departure of this kind of phase retarders is less than 0.36° when the angle of incidence changes between -2°　and +2°.It reserves the merits of normal incidence and normal output in archetypal Fresnel prism, and brings convenience in the operation.