光线斜入射情况下对波片中e光与o光光程差的计算

The Computation of Optieal Path-difference of Ordinary Ray and Extraordinary Ray in Wave Plate under the Condition of Skew-incident Beam

在一般有关晶体光学的教材中，只讨论了光线垂直入射波片时ｅ光与ｏ光的光程差，本文运用惠更斯作图法结合数学方法，推导了波片在光线斜入射时光程差的一般表达式，并给出了由光线斜入射角所引起的光程差变化量的精确计算式，其结论对有关波片和晶体实验及测量具有实际意义。

In general textbook about crystal optical,optical path-difference of ordinary ray and extraordinary ray are discussed only under the condition of normal incident beam.In this paper,we deduce the general representation of optical path-difference by combining the use of method of Huygens' mapping with mathematics under the condition of skew incident beam and give an accurate computing formula in this case.The result has some practical importances for experimenting and measuring the wave plate and crystal.