激光光束检测圆对称超声换能器焦点声压的可行性

根据Raman and Nath理论,光在声场中传播可认为是在多层薄光栅中传播,而薄光栅的参数则由光栅平面内的声场分布决定。本文通过圆对称聚焦换能器在焦平面附近的声场分布,得到光束的偏转角与换能器焦点声压的关系。通过测量光束偏转距离得到换能器焦点声压。虽然本文的声压与偏转角的关系是基于理想超声聚焦换能器的线性理论,但通过激光检测声压与光纤水听器测量的结果,表明该方法可用于检测较高的焦点声压检测。

Feasibility of Circular Symmetric Ultrasonic Transducer Focus Sound Pressure Detection by Laser Beam

According to the Raman and Nath theory, the light propagation in the acoustic field can be considered in multilayer thin grating, and thin grating parameters are determined by the acoustic field distribution of plane grat-ing. Through the acoustic field distribution of the circular symmetry focused transducer in the vicinity of the focal plane, the relationship between the focus sound pressure of transducer and beam deflection angle was gotten. Then focus sound pressure of transducer was gotten by measuring beam deflection distance. Although the relationship be-tween the sound pressure and the deflection angle is based on the idea linear theory of ultrasonic focusing transducer in this paper, compared to the detection results of optical fiber hydrophone, it was showed that it was feasible for the method to detect the higher focus sound pressure.