红外激光窃听器的研制

Design of Infrared Laser Tapping Device

摘要: 近年来红外激光窃听器成为各国研究的热点，针对现有激光窃听器发射接收装置分离调试时间长，本实验设计了一款发射接收一体的激光窃听器采用780 nm红外激光器经准直后照射到模拟声源的玻璃模拟箱中，玻璃表面反射的带有声波信号的激光被光电二极管接收器接收，经过滤波元件LM833、放大元件CA3140所组成的滤波放大电路，最终用音箱还原声音。搭建了实验平台，进行了调试实验，实验得到最佳窃听角度16˚，最佳窃听距离10.2米，窃听效果较好，信噪比约为47.2 dB。

Abstract: In recent years, the infrared laser eavesdropping has become a hot research in many countries. In view of the defects of separation of transmitting and receiving device and debugging with long time in the existing laser eavesdropping device, a portable laser eavesdropping device with Inte-gration of transmitting and receiving was proposed. It used 780 nm infrared laser to illuminate the glass simulation box of the analog sound source. The laser with acoustic signal reflected from the glass surface was received by the photodiode. After LM833 chip filter circuit, CA3140 chip amplifier circuit, the sound was restored by studio monitor. Experimental platform was set up, and the experiment was carried out. The optimal eavesdropping effects with angle of 16 degrees and distance of 10.2 meters are obtained, and the signal-to-noise ratio is about 47.2 dB.