热波探针灵敏度的理论分析

当一束聚焦的、调制的激励激光照射固体材料时，表面上除了产生周期性的温 度分布，还产生局部的周期性形变。在形变区域，探测激光束的反射光受到周期性的偏 转。研究了这种周期性偏转与材料性质和激励激光束参数之间的关系。从热弹性学基本 方程出发建立了数学模型。利用Ｈａｎｋｅｌ积分变换方法得到了交变偏转角的积分表达 式。给出了对于单晶硅的若干计算机模拟结果。

Theoretical Analysis of Sensitivity of Thermal Wave Probe

When a focused, modulated exciting laser beam incidents onto a solid surface, besides generation of periodical temperature distribution, a periodical local surface deformation also occurs. Thus, the reflection angle of a probe laser beam which incidents onto the deformation area will have a periodical component. The relationship between this periodical deflection and material properties and exciting beam parameters is investigated. Based upon general equations of thermoelasticity, a mathematical model is established. By using Hankel integration transformation method, an integral expression for this periodical deflection is obtained. For monocrystalline silicon, some results of computer simulation are given.