Theory and Experiment Study of Ultrasound Generation by Sinusoid Pulse Laser at the Thermoelastic Solid Surface

摘要

Applying one-dimension heat exchange equation and Navier-Stokes equation, the theory model of thermoelastic ultrasound that is generated by laser pulse is established by using simplification sinusoid pulse model, the ultrasound stress pulse is studied. Expressions of stress pulse are attained, which the sample is feebleness absorbability and its surface is freedom or tightening. Imitation and experiment results show stress pulse of tightening surface is monopolar and freedom surface is ambipolar, the breadth of stress pulse is much bigger than the laser pulse'. Increasing thickness of sample, extremum of stress pulse decreases. Also it is much more closed to true skew-Gaussian laser pulse, it has much more universality.