中国科学院云南天文台机构知识库

1m新真空太阳望远镜（New Vacuum Solar Telescope， NVST）的高分辨磁像仪采用了同步重建技术，其中用到了分束镜。分束镜从设计上一般会进行偏振优化，尽量减小偏振效应，但还是不可避免的会对太阳磁场的偏振测量造成影响，因此，对分束镜偏振特性的测量是1m太阳磁场偏振测量的必需步骤。运用空气Mueller矩阵校准法对Mueller矩阵测量结果进行了校准，测量了两块用于磁场偏振测量的分束镜样品，比较了不同分束镜方案的Mueller矩阵及其对偏振测量的影响，并测量了平板玻璃的Mueller矩阵随入射角变化的结果，比较测量结果与理论值之间的偏差，利用空气Mueller矩阵进行校准后测量系统达到5×10（-3）的Mueller矩阵测量精度。 

Synchronous reconstruction technology has been usedin High-resolution magnetographof New Vacuum Solar Telescope, which used beam splitter. The beam splitter isdesigned to reduce the polarization effect, but still inevitably affect the polarization measurement of the solar magnetic field, therefore, the measurement of the polarization characteristics of the beam splitter is necessary for NVST’s polarimeter. In this paper,Mueller matrix of air is used to calibrate the measured Mueller matrix result of samples, and two beam splitter samplesare measured in this method. The Mueller matrix of different beam splitters and their influence on the polarization measurement are compared. The Mueller matrix of the flat glass is measured,which varies with the incident angle, and the deviation between the measured result and the theoretical value is compared. The accuracy of the Mueller matrix measurement system is 5×10-3 after the air Mueller matrix has been used for calibration.