当脉冲激光辐射到样品物体上时,会产生脉冲超声波(包括体波和表面波)。利用脉冲激光作为激励源,可避免与样品的机械接触,可对样品实行远距离的非接触式无损检测。 传统的光声理论利用了经典热弹耦合方程(CTE)该理论假设热扩散的速度为无限大,它的热传导方程是一个抛物型方程。人们利用这个方程在解释实验上 Pulsed ultrasound waves (including body and surface waves) are generated when a pulsed laser is radiated onto a sample object. The use of pulsed laser as the excitation source, to avoid mechanical contact with the sample, the sample can be implemented long-distance non-contact non-destructive testing. The classical photoacoustic theory takes advantage of the classical thermoelastic coupling equation (CTE). This theory assumes that the rate of thermal diffusion is infinite and its heat conduction equation is a parabolic equation. People use this equation to explain the experiment