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为描述飞秒激光烧蚀金属表面过程 ,对双温方程进行了约化。用有限差分法对飞秒、皮秒脉冲激光在金属表面烧蚀过程的温度场进行了一维数值模拟。分析了在飞秒领域对双温方程约化的合理性。计算模型对电子与光子耦合系数的大小对金属表层电子温度的影响进行了分析 ,同时考虑不同脉宽、不同能流及功率密度大小的因素。发现电子与晶格耦合系数影响材料表面电子的温升及电子与晶格温度耦合时间 ;与皮秒激光比较 ,脉冲功率密度是影响电子最终温度的主要因素 ;飞秒激光烧蚀金属材料的厚度可达到表层厚度 (吸收系数的倒数 )量级
To describe femtosecond laser ablation of metal surface processes, the dual temperature equation was reduced. The finite difference method was used to simulate the temperature field of femtosecond and picosecond laser ablation in metal surface. The rationality of double temperature reduction in femtosecond field is analyzed. The influence of the coupling coefficient of electron and photon on the electron temperature of metal surface is analyzed by the calculation model, taking into account the factors of different pulse width, different energy flow and power density. It is found that the electron-lattice coupling coefficient affects the electron temperature and the electron-lattice temperature coupling time. Compared with the picosecond laser, the pulse power density is the main factor affecting the final electron temperature. The thickness of the femtosecond laser ablated metallic material Surface thickness (reciprocal of absorption coefficient) can be achieved on the order of magnitude