光偏转差分表面波探测装置及其蒙特卡罗仿真

基于光偏转测量方法的基本原理,利用平衡接收器的差分电路,建立了光偏转差分式声表面波探测装置,用于对激光超声表面波的探测.该探测系统属光强式探测系统,采用蒙特卡罗算法对探测中的光线传输过程进行了计算机仿真,由此得到探测系统的输出信号与被测声波引起的质点振动速度间存在着线性关系,这一结论与理论推导的结果一致,证明该系统具有较好的线性度,可用于激光超声表面波的探测.

Monte Carlo simulation of differential optical beam deflection system for measuring acoustic surface waves

Based on the underlying principle of the optical beam deflection(OBD) measurement,a differential OBD detection system for the acoustic surface waves(SAWs) is set up.With the differential circuit of the balanced photo receivers,the detection system outputs the difference of detection optical beam powers,which are disturbed by the propagation of the SAWs.This detection system is utilized to detect the laser-generated SAWs.As this system is a light intensity measurement system,the Monte Carlo method is applied to simulate the light propagation in the detection system.So the conclusion,the output of the system is linear to the particle vibration velocity induced by the SAWs,is obtained from the numerical simulation.The conclusion is agreed with the result from the theoretical derivation.It is proved that this detection system with good linearity can be applied to laser-generated SAWs detection well.