Laser shots impact on geometry of crater evolution at copper surface

Abstract

Fine polished 4N (99.99%) pure copper samples are irradiated in ambient air using Q-Switched Nd:YAG Laser (10 mJ, 9-12 ns, 1064 nm). The laser energy density and spot size at tight focus are 3 × 10 11 W/cm 2 and ∼12 μm, respectively. The laser-produced crater is analyzed considering its dimensional changes with the increase in laser shots employing optical microscopy. The width of the crater (along horizontal) increases, thereby exhibiting its exponential trend. The length along the vertical and the depth of the crater both increase exponentially. The heat-affected zone expands exponentially as well. Hydrodynamics and exfoliation are the two main dominant observed ablation mechanisms.