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 CO2 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.