偏光干涉法测量波片相位延迟量和厚度

A polarization interference method for measuring phase retardation and thickness of a wave plate

基于偏光干涉理论,提出一种宽光谱范围内测量波片相位延迟量和厚度的方法。利用矩阵光学方法分析了光谱透射率曲线与中值透射率直线交点波长之间的关系,给出待测波片的相位延迟量、波片厚度等多个物理量的计算公式并进行了误差分析。误差分析表明本方法相位延迟量测量最大误差为3.38°,厚度测量最大误差为0.66μm。实验上利用分光光度计验证了本方法的有效性。本方法能够实现波片多物理量的同时测量,且调节过程对于起偏器、检偏器透光轴方向及待测波片快轴方向无严苛要求,测量过程对波片也无损伤和污染,在波片加工、使用前质量评估等方面都具有一定的应用价值。

Based on the theory of polarization interference, a method for measuring phase retardation and thickness of a wave plate in a wide spectral range is proposed. The relationships of the intersection wavelengths of spectral transmission curve and median transmission line are analyzed by matrix optics method, and the formulas for calculating the phase retardation and thickness of the wave plate are given. Error is also analyzed and it is shown that the maximum error of the measurement of phase retardation and thickness are 3.38°and 0.66μm respectively. The experiment results measured by a spectrophotometer show the validity of this method. The method can measure multiple physical parameters of the wave plate simultaneously, and has some advantages, such as, has no strict requirement for the directions of transmission axes of the polarizer and the analyzer and the fast axis of the wave plate, has no damage and pollution to the wave plate. The method has some application value in the fields of wave plate fabrication and quality evaluation before using a wave plate.