摘要
为了对激光等离子体声信号特性进行深入研究,构建了激光声实验系统。使用波长1.06μm Nd:YAG脉冲激光聚焦击穿水介质产生激光等离子体声信号,使用水听器对信号进行接收,通过高速摄像机对信号产生过程进行了记录。分析了激光等离子体声信号的时频域特征。从理论上研究了激光等离子体声信号的指向性和传输特性,并进行了实验验证。研究结果表明:激光等离子体声信号时域脉宽为15μs左右,频带宽度为200kHz,主频在70kHz左右。信号在不同传输角度上的幅度差异很小,按照近似1/r的规律衰减,传输过程中主频逐渐减小。
The experimental system for laser-induced acoustic signals had been built for research on characteristic of laser-induced plasma acoustic signals. Acoustic signals were produced by pulsed laser focusing into water. A hydrophone was used to receive the acoustic signals. A high speed camera was used to record the breakdown procession. Time and frequency domain of laser-induced plasma acoustic signals were studied. Its directivity and transmission characteristic were analyzed theoretically, and proven by experiment. The results are as follows： The pulse width of laser-induced plasma acoustic signals is about 20μs, its frequency width is 500 kHz and main frequency is 70 kHz. It transmits in all directions and decreases proportionally to 1/r, main frequency decreases as distance increases.
出处
《红外与激光工程》
EI
CSCD
北大核心
2014年第9期2844-2848,共5页
Infrared and Laser Engineering
基金
国家自然科学基金(51109217
51209210)
关键词
激光等离子体声信号
光致击穿
激光光学
水下声波
laser-induced plasma acoustic signal
optical breakdown
laser optics
underwater acoustic signal
