提出基于光学系统的“猫眼”效应，应用单频调制的连续激光，对扫描式红外热成像目标进行有效探测的新方法。分析了光学系统的后向反射特性，针对回波信号特征，提出利用回波信号的相位信息，采用直接采样的数字正交检波技术实现对低信噪比回波信号的可靠检测，并在外场试验中应用该方案对实际目标回波信号获得了满意的检测结果。

Based on the optical systems'“cat's eye”effect,a new technique working with single frequency modulated CW laser against IR scanning imaging systems is provided. The retrodirective reflection of the optical systems against the incident laser is discussed and based on the analysis of echo signals' characteristics. A digital quadrature coherent detector is used to detect such signals with low S/N ratio and the expected results is obtained in experiments.