消色差λ/4波片具有一定的二向色性和相位延迟量误差, 导致仪器偏振测量产生误差。从考虑全偏振CCD相机自身偏振效应的辐射模型入手, 借助积分球辐射源和高精度辅助旋转偏振器, 研究系统级非理想消色差λ/4波片的标定方法。结果发现: 消色差λ/4波片的二向色性和相位延迟量参数随仪器的工作波长与带宽发生变化, 波段650 nm(相位延迟量88.90°)和750 nm(相位延迟量88.65°)消色差效果相对较好, 而波片在波段850 nm(相位延迟量84.33°)相位量偏差较大; 通过相位延迟量的标准误差分析, 得出消色差λ/4波片的系统级标定方法精度优于0.8°。

Polarization measurement error may be caused by achromatic λ/4 wave-plate due to the retarder error and different absorption coefficients for the light oscillating along the fast axis and slow axis of wave-plate. We studied the system-level calibration effect of achromatic λ/4 wave-plate in full-polarized charge coupled-device (CCD) camera based on the radiometric model by using the integrating sphere and the high-precision auxiliary rotation polarizer. Experimental result shows that there are the variation of the retarder and absorption coefficients of achromatic λ/4 wave-plate for the different operating wavelengths and bandwidths in full-polarized CCD camera. The achromatic effects of 650 nm (phase retardation 88.90°) and 750 nm (phase retardation 88.90°) are better than that of 850 nm (phase retardation 84.33°) of our achromatic λ/4 wave-plate in full-polarized CCD camera. The phase retardation precision in our system-level calibration is better than 0.8° through the analysis of phase retardation standard error.