激光诱导声信号通信技术的初步研究

构建了激光声实验测量系统,利用脉冲激光聚焦击穿水介质产生声信号,由水听器将声信号转换成电信号并送入数字存储示波器.分析了激光声信号的时频域数学模型,通过实验对单个激光声信号的时频域特征进行了研究,对激光声通信的信号调制方式进行了理论分析和实验验证.研究结果表明:激光声信号的脉宽约为20s,其能量主要集中在200 kHz内,这其中100~200 kHz内的能量占到的比例大约有50%,通过对激光声信号进行幅度调制和频率调制,可以有效实现激光声通信过程.

Primary research on technology of communication based on laser-induced acoustic signal

Experimental system for laser-induced acoustic signals was built. Acoustic signal was induced by pulsed laser focusing into water. A hydrophone was used to convert acoustic signals into electric signals. The mathematic model for laser-induced acoustic signals in time domain was analyzed. Energy distribution of laser-induced acoustic signals in frequency domain was studied. The modulation method for communication based on laser-induced acoustic signal was theoretically studied and proved by experiments. The results are as follows: Pulse width of laser-induced acoustic signal is about 20s. The laser-induced acoustic signals have most of their energy concentrated within 200 kHz, where half of that is between 100 kHz and 200 kHz. Magnitude modulation and frequency modulation are effective methods in communication based on laser-induced acoustic signal.