法拉第镜旋转角的偏振分束测量法

Polarization-beam-splitter measurement of rotary angle for Faraday mirror

提出了基于偏振分束法的法拉第镜偏振旋转角的测量方法。利用非偏振分束器改变法拉第镜出射光的方向,偏振分束器将该出射光分为p光和s光,分别测量其光强,应用后续"差除和"信号处理方案消除光源波动的影响,推导出法拉第镜偏振旋转角的理论表达式。分析了起偏器的消光比非0及起偏角误差对输出结果的影响,分别是0.05729°和-0.1000°。实验验证了该方法的可行性,重复测量结果为89.68°,均方值为0.01493。

The measurement of polarization rotary angle for faraday mirror based on polarizationbeam-splitter was proposed. The orientation of through a non-polarized beam splitter （NPBS）. the light from the faraday mirror was changed With a polarized beam splitter （PBS）, the light reflected from NPBS was split into S light and P light. Their intensities were measured, and the theoretical expression of rotary angle was deduced after the impact of optical fluctuation is eliminated by signal processing. The influence of non-zero extinction ratio and polarized-angle error on output results was analyzed. Finally the intensities were repeatedly measured, and the average rotary angle was 89. 68°, the mean square deviation of all the experimental data was 0. 014 93.