Drilling with a novel high-power Q-switch pulse laser

Abstract

This paper reports on the characterization and analysis of drilling with a novel high power acousto-optical Q-switch pulse laser. The laser is a flash-lamp pumped pulse Nd:YAG laser which can be used in the free running mode with repetition rates up to 10Hz. Additionally it is possible to modulate these pulses using acousto-optical modulator which enables a burst between 1 and 10 Q-switch pulses with a duration of typically 200ns during each flash-lamp pulse. The repetition rate of the burst is 5kHz-50kHz, the pulse energy is 30-8OmJ, and the peak power is more than 400kW with a beam parameter product of about 5mm mrad. The drilling process and the combination of different repetition rate of the bursts enables drilling 2.5mmthick Cu and Ni-alloy for 0.2mm micro-hole. The recast layer is nanower. Oxidation of the walls of the hole is prevented by a high-pressure inert gas.