Effect of dual ultrashort laser pulses on metal ablation for efficient micromachining

The properties of laser ablation of metallic targets with ultrashort single and double pulses with a similar total energy were investigated for two target materials: silver and copper. The numerical analysis was performed using the developed FEMTO-2D computer package developed by the authors based on the solution of a two-temperature model. The thermal dependence of the target optical and thermodynamic processes and their role in the overall target response to dual pulse laser irradiation were carefully considered. The ablation rate for a dual pulse laser machining at the optimal pulse separation time was found to be similar (for silver) or above (for copper) the ablation rate for a single pulse machining for the same total fluence. The advantages of using dual pulse laser micromachining are reduced maximum electron temperature and increased lattice temperature in the ablated region predicted by the model developed by the authors. (c) 2018 Laser Institute of America.