激光超声的原理及其在固体中的应用

激光超声是指脉冲激光所产生的脉冲超声。激光超声是较新的产生超声的方法。它的主要特色是，可以遥发遥收，这样就有可能在高温、有危险辐射等恶劣环境下以及在样品运动的生产线上进行超声检测。皮秒级和飞秒级的激光所激发的超声近来又用来研究固体中电子和声子的相互作用。文章介绍了固体中激光超声的声学性能及两种产生机理：热弹机理和电子机理。

Laser-Generated Ultrasound:its Physical Principles and Applications in Solids

Laser-generated ultrasound denotes the pulsed ultrasound excited in a medium by a pulsed laser. This is a relatively new means of generating ultrasound, the main advantage of which is that the ultrasound may be remotely excited (and recepted), and thus may be applied to material e- valuation in hostile environments like elevated temperatures and dangerous radiation as well as on the preduction line with fast-moving products. Ultrasound excited by pico-second or femto-second lasers has recently been used to study the coupling of electrons and phonons in solids. This paper reviews the acoustical properties of laser ultrasound in solids and two important mechanisms of generation, the thermal and the electronic.