School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Opt Lett. 2012 Jul 1;37(13):2691-3. doi: 10.1364/OL.37.002691.
Ultrafast laser-induced melting in a gold thin film is simulated by an integrated continuum-atomistic method with the extended Drude model for dynamic optical properties. The local order parameter of atoms is used to identify solid and liquid regions. It is shown that the film is superheated in the early nonequilibrium stage and the melted region grows very quickly with a very high rate of melting up to ∼13,300 m/s. It is also found that the continuum approach could significantly underestimate the ultrafast phase-change response, and temperature-dependent optical properties should be considered in atomic-level modeling for ultrafast laser heating.
采用扩展德拜模型的连续-原子集成方法模拟了金薄膜中的超快激光诱导熔融。原子的局域序参量用于识别固液区域。结果表明，在早期非平衡阶段，薄膜过热，熔融区域快速增长，熔融速率高达约 13300 m/s。还发现连续体方法可能会显著低估超快相变响应，在原子级模拟超快激光加热时应考虑温度相关的光学性质。
