激光窃听实验探究

Experimental research on laser eavesdropping

提出了一种激光窃听模型,并简要地介绍了其实现方法.声音信号在玻璃表面会产生声压,驱动玻璃做受迫振动,使其在激光入射点附近做近似垂直振动,玻璃的微小位移使得反射激光的光轴也发生相应线性的位移.在接收端,通过探测射到光电检测器窗口的光斑面积的变化,可将光信号转变为电信号,再经过放大等处理,实现声音的还原,达到窃听的效果.

A theoretical model of laser eavesdropping is put forward; its realization is introduced briefly. The sound pressure induced vibration of glass leads to micro-displacement of the glass. If the glass vibrated vertically at the approximate incident point of the laser, the axis of the laser will move linearly. Therefore, laser eavesdropping can be achieved by measuring the changes of the area of the laser spots on the photoelectric detector. After changing optical signal into electrical signal and signal amplification, the sound can be restored.