空间平均型退偏要求退偏后的光束不仅具有低偏振度, 还要求避免偏振态的空间带状连续分布.为了实现光束偏振度的测量和空间退偏度的观察, 提出基于洛匈棱镜的偏振度测量方法, 理论推导了偏振度和各个光功率测量值之间的关系, 设计了实验装置, 并与全偏振度测量方法进行对比.结果显示: 两种测量方法得到的偏振度相对偏差为0.192%, 但洛匈棱镜能将o光和e光在空间分离, 能对光束偏振态的空间分布进行观测.基于洛匈棱镜的偏振度观测方法结构简单, 操作方便, 在偏振度和偏振态的空间分布的同时观测中有重要应用.

Spatial averaged depolarization requires that depolarized light beam not only has a low degree of polarization(DOP), and also avoids the polarization state exhibiting continuous band in spatial distribution.To achieve the measurement of the DOP of the beam and observation of the degree of spatial depolarization, a method based on the Rochon prism was proposed.The dependence of the DOP on each optical power measurements was firstly deduced, following with experimental measurement and comparison to full polarization test method.The relative deviation in the DOP for the same light beam, 0.192%, shows the two methods have the same performance in measurement of DOP.However, the feature of the proposed method separating o component and e component in the space enable observations of the spatial distribution of polarization states respectively.The Rochon prism based method will play an important role in simultaneous measurement of DOP and observance of spatial polarization distribution.