Simulation Study of Thermal and Mechanical Effect on Metal Film Irradiated by Ultra-fast Laser Pulse
超快脉冲激光辐照金属薄膜热-力效应的模拟研究

Based on the dual-temperature hyperbolic two-step heat conduction and hot- electron blast models,a new set of fully coupled and nonlinear ultra-fast thermo-elasticity model was derived to investigate the thermo-mechanical coupling effect of metal films caused by ultra-fast pulsed laser.Taking the 200nm gold film irradiated by a 100fs laser pulse as a typical example,thermal stress development in the lattice sub-system,temperature along with temperature gradient and electron heat flux were modeled by using artificial viscosity and the adaptive step finite-difference algorithm.It is shown that the early period of laser heating is a non-equilibrium process and forming large hot-electron blast force.It is also found that electron heat flow presents bimodal phenomenon.In addition,thermal stress induced by ultra-fast laser heating could be the main reason for mechanical damage.