Ultrashort pulse laser heating is not only capable of resolving and observing the ultrafast interaction of energy carriers, I. E. Electrons, phonons, but also widely applied to material processing, I. E. , laser ablation. However, the previous theories, I.e. , two-temperature model, parabolic one-step model, can be applied only to some limited segments. In this paper, according to the two-temperature model and Fourier' s law, a general theoretical model is presented for the description of the entire heat relaxation process after the thin metal film deposited on the substrate has been heated by the ultrashort pulse laser. Moreover, the heat conduction process is also experimentally studied by using the rear-pump front-probe transient thermoreflectance technique on Au/glass and Au/SiC at 300 K, and the theoretical prediction accords well with the experimental result, which illustrates the validity of the present theoretical model. Based on the good agreement between theoretical predictions and experimental data, the electron-phonon coupling factor of the thin gold film and thermal boundary conductance of the Au/glass and Au/SiC interfaces are extracted and the measured results are in good agrement with the previous reported values. The electron-phonon coupling factor is close to that of the bulk material and does not exhibit size effect. The thermal boundary conductance is greater than the prediction of diffuse mismatch model, and the reasons responsible for the discrepancies are electrons participating in the interfacial heat conduction, interfacial atom diffusion and inelastic scattering.%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300 K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.
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