格兰-泰勒棱镜光强透射比波动的成因及抑制方法精确分析

Precise Analysis of Formation and Suppression of Intensity Transmittance Fluctuations of Glan-Taylor Prisms

格兰-泰勒棱镜的光强透射比随着空间入射角的改变会出现波动。借助共点三轴系统和多光束干涉公式,得到了偏光棱镜的光强透射比的精确表达式。根据马吕斯定律,利用数值模拟实验,给出了格兰-泰勒棱镜作为检偏镜在光学系统中的光强透射比表达式。数值模拟结果表明:波动的产生来源于平行空气隙间的多光束干涉,波动幅度的大小及出现的位置主要取决于空气隙的平行程度及检偏镜在光学系统中的相对位置。令棱镜的转轴和系统的光轴之间的夹角β=0°,可以实现光强透射比曲线上波动的完全抑制。给空气隙一个小的胶合误差角可以有效抑制光强透射比随空间入射角的波动。抑制波动的临界胶合误差角随入射光束横截面的增大而减小。

The light intensity transmittance of Glan-Taylor polarizing prism suffers from fluctuations in spatial incident angle. By using three-axis model and multibeam interference theory, we develop the expression of light transmittance of the prism in spatial incident angle. Based on Malus law, the light intensity transmittance of the analyzer in optical system is simulated, which shows that the fluctuations on intensity transmittance curve result from the multibeam interference in the parallel air gap, and the magnitude and position of the fluctuations lie on the parallelism of the air gap and the spatial position of the prism in the optical system. The intensity fluctuations can be completely suppressed with the angle between the rotation axis of the prism and the optical axis ~= 0 o. For/9：/-0 o, by giving the air gap a glued error angle, the transmittance fluctuations are well suppressed. The critical glued error angle for suppressing fluctuaitons decreases with the increase of the incident spot size,