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超短脉冲激光加热可应用于研究材料中载能子之间的超快相互作用,同时也广泛应用于超快激光加工.此前人们提出的双温度模型和抛物一步模型都只能用于描述超短脉冲激光加热金属薄膜后热量传递过程的特定片段.基于双温度模型和傅里叶导热定律,提出普适的理论模型可用于完整描述飞秒激光加热金属薄膜/基底时的整个热量传递过程.同时在300K温度下,采用背面抽运-表面探测瞬态热反射法实验研究了飞秒脉冲激光加热金属薄膜的热量传递过程,理论预测曲线和实验测量结果符合较好,验证了理论模型的正确性.基于此模型测量得到了金薄膜的电子-声子耦合系数和金/玻璃,金/碳化硅间的界面热导,测量结果和文献报道值符合较好.其中电子-声子耦合系数和体材料值接近,没有表现出明显的尺寸效应.界面热导比散射失配模型的预测值大,可能是电子参与界面导热、界面原子扩散及声子在界面的非弹性散射等造成的.
Ultrashort pulse laser heating can be used to study the ultrafast interaction between energetic materials in materials, and is also widely used in ultrafast laser processing. Previously, both the dual temperature model and the parabolic one-step model can only be used to describe ultra Based on the dual-temperature model and Fourier’s thermal conductivity theory, a universal theoretical model is proposed to describe the whole heat transfer process of femtosecond laser when the metal thin film / substrate is heated. At the same time, the thermal transfer process of femtosecond pulsed laser heating metal thin film was studied by the back-pumping-surface detection transient heat reflection method at 300K temperature. The theoretical prediction curve and the experimental measurement results are in good agreement with each other, which proves that the theoretical model is correct The electron-phonon coupling coefficient and the interface thermal conductance between gold / glass and gold / silicon carbide were measured based on the model, and the measured results are in good agreement with the reported values. The electron-phonon coupling coefficient The values of bulk materials close to each other, and no obvious size effect is shown.It is predicted that the interfacial thermal conductivity is larger than that predicted by the scattering-mismatch model, Heat, interface atom diffusion and phonon at the interface caused by inelastic scattering.