晶体应力光学系数的研究

在以往关于晶体材料的应力双折射的标准中，都忽略了晶体在光弹方面所表现出的特殊性质，而将其与玻璃等同起来，应力仅以材料最长边中部或边缘单位长度上的光程差来表示。这与实际情况相差很大。本文从结构对称的立方晶系晶体入手，深入研究了晶体应力光学系数这一参量，提出晶体的应力光学系数不仅取决于材料，还与应力的取向、观察者的观察方向有关。并发现立方晶系晶体（１１１）面具有各向同性性质和在［１１１］方向应力状态下应力光学系数与观察方向无关的特性。另外还发现光波进入有应力的晶体后所分解的两束相互垂直的偏振光，有时其振动方向并不与应力方向平行，而是发生了偏转。这些研究将为晶体应力测量提供了科学依据

Study on stress optic cofficient of crystal

Crystals are different from isotropic materials like glasses in photoelasticity. So we cant express the stress birefringence of crystals only with double refraction retardation in nm/cm. In this paper, we deeply study the ralative stress optical cofficient (Brewsters coefficent) of cubic crystals, and put forward that the ralative stress optical coefficients of crystals relate not only to the kind of materials, but also to the directions of stresses and observations. In the studies, we also find that the (111) face and direction have isotropic property in cubic crystals. In addition, we find sometimes the polarized directions of light which incident in stressed crystals are not parallel to the directions of stresses. All of these studies will provide scientific basis for measuring residual stresses in crystals.