Heat transfer from a modulated laser incident on a multilayered thin film material is theoretically analyzed as a continuum system accounting for thermal contact resistance between the layers and anisotropy of thermal conductivity of the films. Formulations are obtained for the intensity-averaged deflection of a probe beam (PB) laser bounced on the surface as it passes through the thermally excited region of the gas. The PB formulations are the basis for nonintrusively measuring material properties. An algorithm is used to determine property values by matching measured and simulated PB deflections with selected properties as fitting parameters. Experiments are reported to provide data for validating the PB formulations for bulk standard reference and film/substrate materials. For the latter, a virtual film bonded to a substrate of the same material was used. Results show that predicted and measured PB deflections are in good agreement for thin films when the modulation frequency positions the thermal penetration depth inside the film. It is also shown that for increasing thermal contact resistance, anisotropy of thermal conductivity of the film materials, and modulated beam radius and frequency, the PB deflections are reduced through the effect of these variables on heat flow in the solid and gas.

入射到多层薄膜材料上的调制激光的热传递在理论上被分析为连续系统，考虑了层之间的热接触电阻和薄膜的热导率的各向异性。当探测光束 (PB) 激光穿过气体的热激发区域时，在表面上反弹的探测光束 (PB) 激光的强度平均偏转公式是获得的。PB 公式是非侵入式测量材料特性的基础。一种算法用于通过将测量的和模拟的 PB 挠度与选定的特性作为拟合参数进行匹配来确定特性值。据报道，实验提供了用于验证批量标准参考和薄膜/基材材料的 PB 配方的数据。对于后者，使用粘合到相同材料的基板的虚拟膜。结果表明，当调制频率定位薄膜内部的热穿透深度时，薄膜的预测和测量的 PB 偏转非常一致。还表明，为了增加接触热阻、薄膜材料的热导率的各向异性以及调制光束半径和频率，通过这些变量对固体和气体中热流的影响，PB 偏转减少。