为了实现对Si、Ge、GaAs等红外材料应力缺陷检测，采用两个工作在不同频率的光弹性调制器级联，构成偏振测量系统。应力缺陷引入的双折射延迟量和快轴方位角两个参数，被加载到偏振测量系统调制信号中；利用数字锁相技术同时获取调制信号的基频项和差频项幅值，然后完成两个应力参数求解。详细分析了检测原理，并搭建了实验系统进行验证。实验结果表明，该检测方法及实验系统实现了应力方向角标准偏差为0.31°，应力双折射延迟量标准偏差为0.72 nm，高速、高精度和高重复度的应力缺陷检测，并且实现了Ge样品的应力缺陷方向和值大小分布测量，可为红外材料质量测试分析和评估提供有效手段。

In order to achieve the stress defect detection of infrared materials such as Si, Ge, and GaAs, two Photoelastic modulators working at different frequencies are cascaded to form a polarimetry system. The birefringence retardation and fast axis azimuth introduced by the stress defect are loaded into the modulation signals of the polarimetry system. The amplitudes of the fundamental and differential frequency terms were simultaneously obtained by using digital phase-locked technology, and then the two stress parameters are solved. A detailed analysis of the detection principle was conducted and an experimental system was established for verification. The experimental results show that this method has achieved stress defect detection with a standard deviation of 0.31 ° for stress direction angle and 0.72 nm for stress birefringence retardation. The high-speed, high-precision, and high repeatability stress defect detection are realized, and the measurement of stress defect distribution in a Ge samples are demonstrated. An effective method for infrared material quality testing, analysis, and evaluation is proposed.