通过双温方程对飞秒单脉冲与双脉冲照射金薄膜进行了计算模拟分析,得到了金靶的电子温度和晶格温度随着时间空间的变化。在同样激光能量密度下,单脉冲与双脉冲使得金膜温度的变化表明双脉冲使得更多的激光能量渗透到靶材内部,这些能量可以使得烧蚀深度更深,有利于提高激光烧蚀靶材的效率。计算结果显示随着激光能量密度的增加熔化面深度逐渐增加,单脉冲与双脉冲熔化面深度的变化明显不同。在激光能量密度高于损伤阈值附近,单脉冲的烧蚀深度大于双脉冲的烧蚀深度,随着激光能量密度增加,双脉冲的烧蚀深度将大于单脉冲的烧蚀深度。

The thermal behaviors of gold film under femtosecond single pulse irradiation and double pulse laser irradiation are calculated by the two-temperature equations. The temporal-spatial distributions of electron temperature and lattice temperature are obtained. At the same laser fluence, than that by the single pulse, the calculated results indicated more laser energy will penetrate into the internal target by the double pulse. The ablation depth will be enhanced. It will help us to improve the efficiency of femtosecond laser ablation of target. The evolution of first melted front is different of single pulse and double pulse ablation with different laser fluence. Near the damage threshold, the ablation depth of single pulse is greater than that of the double pulse. With increasing the laser energy density, the ablation depth of the double pulse is greater than that of the single pulse.