Heat-affected zone and ablation rate of copper ablated with femtosecond laser
Heat-affected zone and ablation rate of copper ablated with femtosecond laser
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DOI：
10.1063/1.1852692
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发表时间：
2005-03-15
影响因子：
3.2
通讯作者：
Obara, M
中科院分区：
文献类型：
--
作者：
Hirayama, Y;Obara, M
我们描述了飞秒激光烧蚀晶体铜（Cu）的实验和分子动力学模拟研究。本文主要研究飞秒激光烧蚀后的热影响区和激光烧蚀率。作为烧蚀表面上的X射线衍射测量的结果，表面的结晶度部分地从晶体结构变为非晶结构。在低于烧蚀阈值的激光能量密度下，耦合到Cu靶的全部激光能量被吸收，而在超过阈值能量密度的能量密度范围期间，烧蚀速率取决于吸收系数，并且不用于烧蚀的剩余能量留在Cu衬底中。在低于阈值的注量处的热影响区估计大于阈值注量处的热影响区。此外，本文还采用双温模型和分子动力学（MD）模拟方法对激光烧蚀Cu的过程进行了理论研究，解释了激光烧蚀Cu的热影响区和烧蚀速率。分子动力学模拟考虑了由双温模型计算的电子温度和热扩散长度。晶格温度随时间和深度的变化计算的MD模拟耦合的双温度模型。对实验测得的烧蚀率和热影响区进行了理论解释。(C)2005年美国物理学会。
We describe the experimental and molecular dynamics simulation study of crystalline copper (Cu) ablation using femtosecond lasers. This study is focused on the heat-affected zone after femtosecond laser ablation and the laser ablation rate. As a result of the x-ray diffraction measurement on the ablated surface, the crystallinity of the surface is partially changed from a crystal structure into an amorphous one. At the laser fluences below the ablation threshold, the entire laser energy coupled to the Cu target is absorbed, while during the fluence regime over the threshold fluence, the ablation rate depends on the absorption coefficient, and the residual energy which is not used for the ablation, is left in the Cu substrate. The heat-affected zone at the fluences below the threshold is estimated to be greater than that over the threshold fluence. In addition, the laser ablation of Cu is theoretically investigated by a two-temperature model and molecular dynamics (MD) simulation to explain the heat-affected zone and ablation rate. The MD simulation takes into account the electron temperature and thermal diffusion length calculated by the two-temperature model. Variation in the lattice temperature with time and depth is calculated by the MD simulation coupled with the two-temperature model. The experimental ablation rate and the heat-affected zone are theoretically well explained. (C) 2005 American Institute of Physics.