基于四象限探测器的斯托克斯向量测量仪

A Stokes polarimeter based on four quadrant detector

四象限探测器的各探测器互相匹配,被广泛应用于光束准直等应用中,适合于测量和监控快速变化或漂移的光束.通过研究,提出了一种基于四象限探测器的偏振态测量装置.该装置在四象限探测器的每一个探测器前放置经过不同检偏方向的偏振片及特定相位延迟和快轴方向的波片,构成四个检偏通道,并通过探测器上的光强计算得到入射光的斯托克斯向量.不同偏振片的偏振方向以及波片的相位延迟和快轴方向经过优化设计确定,以便降低测量误差并提高测量稳定性.该斯托克斯向量测量仪能够实现入射光偏振态的同时测量与高速输出,对于动态偏振系统的监控具有独特优势.通过类似优化设计,亦可扩展系统使用波段,改善红外波段测量效果.

Four-quadrant detectors which consist of four well balanced detectors have been used for beam collimation and target tracking. In this article,we report a Stokes polarimeter based on a four-quadrant detector. By placing polarizers and wave plates in front of the individual detectors,the four detection channels were turned into four polarization analyzing channels of a Stokes polarimeter. An optimization algorithm was proposed to determine the axis directions of the individual polarizers,as well as the axis direction and the retardance of the wave plates for minimizing the errors and increasing the robustness of the measurements. The polarimeter is capable of simultaneous measurements of fast varying polarization states. Using properly selected polarization optics and following the same optimization algorithm,the polarimeter can be extended to other wavelength range,such as the infrared.