基于激光测振法的高强度超声声场测量

High-intensity Ultrasonic Sound Field MeasurementBased on Laser Vibrometry

基于激光测振法对高强度聚焦超声换能器的辐射声场进行测量,与标准水听器测得的结果对比焦点处基波信号、二次谐波、三次谐波测得值基本一致,基波声压误差在10%以内,焦平面的声压分布基本一致。同时,基于多层介质阻抗传递法解决激光测振法中薄膜对声场测量的影响,计算不同频率下薄膜的声压透射系数。设计实验验证不同频率(1、5、10 MHz)下,激光测振法与标准水听器测量法得到的结果,结果表明通过声压透射系数对激光测振法测量结果进行修正可有效减小测量误差。

The radiated sound field of the high intensity focused ultrasonic transducer is measured based on the laser vibration measurement method.Compared with the results measured by the standard hydrophone,the measured values of the fundamental wave signal,the second harmonic and the third harmonic at the focus are basically consistent.The error of the fundamental wave sound pressure is within 10%,and the sound pressure distribution at the focal plane is basically consistent.At the same time,the influence of the thin film on the sound field measurement in the laser vibration measurement method is solved based on the multilayer dielectric impedance transfer method,and the sound pressure transmission coefficient of the thin film at different frequencies is calculated.Experiments are designed to verify the results obtained by the laser vibrometry method and the standard hydrophone measurement method at different frequencies(1 MHz、5 MHz、10 MHz).The results show that the correction of the measurement results of the laser vibrometer method by the sound pressure transmission coefficient can effectively reduce the measurement error.