分时偏振光谱测量系统的起偏效应校正

Calibration of polarized effect for time-divided polarization spectral measurement system

针对实验室偏振光谱测量系统短波红外起偏效应大、测量偏差大的问题,建立了系统目标斯托克斯校正模型,提出了该模型中相关系数的测量方法,从而实现了系统偏振效应的精密校正。首先分析了实验室常用的低成本分时偏振光谱测量系统存在的主要问题及起偏效应的来源。然后根据偏振传输理论,将系统中起偏效应较大的波谱仪等效为检偏系统,建立了目标偏振信息的校正模型,并通过与理想模型的对比验证了模型的正确性。最后针对本测量设备,为提高校正系数的测量精度,在解析法的基础上提出了一种更精确的拟合法。实验结果表明,本方法的校正精度高于0.5%,满足实验室中对目标偏振信息处理的精度要求,对偏振光谱测量系统的研制和标定具有指导意义。

Aiming at the problems of polarizing effect in short wave infrared and measurement deviation in the polarization spectral measurement system built in lab,a system calibration model was established and a method to measure the correction coefficients of the model was proposed,thus the polarizing effect was calibrated precisely.Firstly,the main problem of the regular time-divided polarization spectral measurement system was described and the origin of the polarizing effect was analyzed.An ASD spectrometer which had a serious polarizing effect functioned as an analyzer according to the polarization transmission theory.Thereby a system calibration model was established and verified by comparing with the ideal model widely used.Then,a high precision fitting method of the correction coefficients was proposed for improving the measurement accuracy based on the analytical method.Experimental results indicate that the calibration precision is higher than 0.5%,which can fully satis-fy the requirements of target polarization information processing in laboratory.This method has a great significance for the development and calibration of polarization spectra measurement system.