飞秒激光加热多层金属薄膜的热响应

采用微观双曲两步热传导模型,研究了飞秒脉冲激光加热过程中多层金属薄膜的热响应。利用界面连续条件,推得三层金属薄膜各层薄膜内电子温度和晶格温度在拉普拉斯域内的解析表达式。通过拉普拉斯数值反变换,计算并绘制了100nm单层Au膜和34nmAu/33nmCr/33nmAu三层膜在飞秒脉冲激光加热过程中各层薄膜内电子温度和晶格温度沿薄膜厚度的分布曲线。数值结果表明,激光加热过程中不仅电子与晶格之间存在强烈的非平衡热行为,不同金属材料薄膜界面上金属晶格温度也具有急剧的非平衡行为。同时讨论了多层薄膜温度分布特点及其与薄膜材料参数的关系。

Thermal Response of Multi-Layer Thin Metal Film Structure During Femtosecond Laser Heating Process

Using hyperbolic two-step heat conduction model, thermal response of multi-layer thin metal film is studied during short pulse laser heating process. Using consecutive conditions on interfaces, the expressions of electron gas and lattice temperature in Laplace transfonn domain are obtained for each layer of the three-layer thin metal film. Electron gas and lattice temperature profiles in each layer, 100 nm gold film and 34 nm gold film/33 nm Cr film/34 nm gold film, are obtained by numerical inverse. The numerical results show that the considerable nonequilibrium heat behavior arises both between the electron gas and the lattice, and at the interface between two metal materials during the heating process. The effects of material constants of the thin film on thermal response are discussed.