利用琼斯矩阵,找到了消光比和应力双折射相位差的关系,利用旋转样品法测量了晶体的消光比,给出了表达式,并对误差进行了理论分析。使用功率不稳定度小于0.2%的光源、消光比高于50 dB的起偏器搭建了测试系统。测试系统适用于相位差在(π/2,π)范围的待测样品,测试精度小于-55 dB。对1/2波片进行测量,结果表明,其消光比为-41.66 dB,综合误差小于1%。

The relationship between the extinction ratio and the stress birefringence phase difference is identified based on a Jones matrix. The extinction ratio of a crystal is measured by the rotating sample method, its expression is also derived, and the errors are analyzed theoretically. A light source with power instability lower than 0.2% and a polarizer with an extinction ratio higher than 50 dB are used to build the test system. This test system is suitable for testing the samples with phase differences in the range of (π/2, π), and the test accuracy is less than -55 dB. The measured extinction ratio of a 1/2 wave plate is -41.66 dB, and the comprehensive error is less than 1%.