Laser ablation of Si, Ge, ZrO₂and Cu in air

Abstract

Si, Ge, ZrO2 and Cu were irradiated by air by 1.06 mu m 10 ns laser pulses with a high intensity of 6.4*109 W cm-2. Detailed scanning electron microscopy (SEM) and ablation crater profile measurements were made. The results indicated that the ablation rates of these materials under intense pulsed laser irradiation are quite high. The refractory oxide ZrO2 has the highest material removal rate. Evidence of liquid material flushed out of the ablation craters was observed for all the materials studied with the exception of Cu. Gas dynamic velocities of transient thermal vaporization were calculated using self-similar solutions of the gas dynamic equations. Using these parameters, material removal rates were calculated and the results compared with the experimentally measured values. Possible ablation mechanisms of these materials under the irradiation conditions used in the present work were discussed.