脉冲CO2激光水下致声声脉冲特性的实验研究

以分析水中的光声信号的特点为目的,采用实验的方法利用压电陶瓷球形水听器、数字存储示波器,对TEACO2脉冲激光在水中激发声波的幅度、频率等特性进行了测量,并用信号分析软件进行分析和处理。结果表明,TEACO2脉冲激光在水中产生的声信号幅度随脉冲能量增加而增大。实验中首次发现,激光声频率在100kHz以内有31kHz和62kHz两个峰值,且该两频率峰值随激光脉冲宽度增加而减小。光声信号的以上特性表明,可以通过调节激光脉冲的能量和宽度,选择或控制应用于水声通信、水下资源探测等技术的光声信号。

Experiment research of acoustic effect induced by pulsed CO2 laser in water

In order to get the characteristics of laser ultrasound in water,a spherical ceramic hydrophone and a digital oscilloscope were used to receive,demonstrate and store the optoacoustic signal induced by a TEA CO_2 pulsed laser.Later the digital signal was analyzed and handled with a computational software.The experimental results showed that:the amplitude of the signal increased with the laser pulse energy and the signal had frequency peaks at 31kHz and 62kHz below 100kHz.Furthermore the peak frequencies decreased when the laser pulse width increased.The above results mean that applicable laser ultrasound source with higher amplitude and lower frequency,which can be used in underwater communication and underwater detection,can be chosen and acquired by adjusting the energy and width of laser pulse.