论文标题
通过超短激光脉冲熔化：高级两温建模和与表面损伤实验的比较
Melting of gold by ultrashort laser pulses: Advanced two-temperature modeling and comparison with surface damage experiments
论文作者
论文摘要
金属中超快速激光诱导的固液相变过，其准确的定量描述仍然是一个挑战。在这里，我们在实验和理论上系统地研究了单个Femto和Picsecond近红外激光脉冲熔化的金。使用了两个激光系统，波长为800和1030 nm，脉冲持续时间范围从124 fs到7 ps不等，并确定了每种辐照条件的损坏和消融阈值。理论分析基于两个温度的建模。检查了电子晶格耦合率的不同表达式和弹道电子的贡献。另外，建议参与光学响应的游离电子数量取决于激光强度以及所涉及电子对损伤阈值的影响。建模参数的组合只能始终如一地描述所有测量的损伤阈值。提出了物理参数来解释建模结果。
The ultrafast laser-induced solid-liquid phase transition in metals is still not clearly understood and its accurate quantitative description remains a challenge. Here we systematically investigated, both experimentally and theoretically, the melting of gold by single femto- and picosecond near-infrared laser pulses. Two laser systems with wavelengths of 800 and 1030 nm and pulse durations ranging from 124 fs to 7 ps were used and the damage and ablation thresholds were determined for each irradiation condition. The theoretical analysis was based on two-temperature modeling. Different expressions for the electron-lattice coupling rate and contribution of ballistic electrons were examined. In addition, the number of free electrons involved in the optical response is suggested to be dependent on the laser intensity and the influence of the fraction of involved electrons on the damage threshold was investigated. Only one combination of modelling parameters was able to describe consistently all the measured damage thresholds. Physical arguments are presented to explain the modeling results.
