一种利用电光效应测量微小转角的新方法

Mini-rotating-angle Measurement Based on the Linear Electrooptic Effect: A New Method

利用线性电光效应发展出一种新的、高准确度的微小转角测量法·根据W.L.She等人提出的线性电光效应耦合波理论,求得出射光强与入射光强比值(即出射率)对入射光方向的依赖曲线,利用该曲线,通过测量出射率可以确定入射光的方向·并根据此原理,设计了一套简单的装置,该装置可以测量出物体微小转角的变化量,同时测量范围及准确度都可通过外加电场和入射光波长加以调节·对此微小转角测量法作了理论分析,在Li NbO3器件上,得到测量范围大于3′,准确度为3.5″的设计结果·

Using the wave coupling theory of the linear electro-optic effect, a new method to measure minirotating-angle is developed,which is with high precision. According to the wave coupling theory of linear electrooptic effect, advanced by W. L. She et al.. The relation between the output intensity and the incident angle is formulated. That is to say, the displacement of the incident angle could be determined accurately by measuring the output intensity. Based on this principle, a simple system was presented to measure the small rotating-angle of an object, meanwhile, its measurement range and accuracy could be modulated by changing the external electric field or the wave length of incidence. Its measuring accuracy can be 3. 5＂ within the measurement range of 3＇ when the electro-optic crystal is LiNbO3.