为了提高空间振幅调制光谱偏振测量系统中光谱偏振数据和图像的采样精度, 对偏振调制模块-双复合光楔调制器的消色差特性进行了研究.根据双复合光楔的消色差原理及其结构形式, 分析了不同双折射晶体材料构成的双复合光楔调制器相位延迟量的一阶导数与晶体材料双折射率、楔角的关系, 并利用Matlab软件数值模拟寻找最优组合.基于理论分析, 采用KDP-石英组合与石英-石英组合进行对比实验, 结果表明：KDP-石英组合一级亮条纹相位延迟量对波长的一阶导数数值小于石英-石英组合, 证明了KDP-石英组合消色差特性优于石英-石英组合, 其结果与理论分析一致.

The achromatic characteristic of polarization modulation module- double combo wedges modulator was studied, in order to improve the sampling accuracy of spectral polarization data and image in spatial modulating spectropolarimetry. According to the achromatic principle and the structure of the double combo wedges , the relationship between the first derivative of the phase retardance of the double combo wedges modulator and the birefringence and the wedge angle was deduced, which the double combo wedges modulator was composed by different birefringent crystal materials. The Matlab program was used to find the optimal combination. Based on the theory, the experimental contrast was carried on with KDP-Quartz and Quartz-Quartz combination .The experimental results show that the data of the first-order bright stripe of the KDP-Quartz combination is smaller than that of the Quartz-Quartz combination. The achromatic characteristic of KDP-Quartz combination is better than that of Quartz-Quartz combination, which is consistent with the theoretical analysis.