Piezo-based Beam Shaping for High Dynamic Three-dimensional (3-D) Laser Material Processing – PISTOL
L. Devaraj Nair, C. Goppold, P. Böttner, D. Stoffel, A. Jahn, C. Jolliffe and M. Bach
Laser machining processes get more and more relevant for a vast number of industrial applications such as cutting, welding, ablation and surface treatment. These processes can be enhanced through high-speed active vertical shift of the beam energy within the workpiece. A piezo-driven dynamic focus shifter provides the opportunity to the vertical oscillation frequency in a robust and reliable manner. Up to a drive frequency of approximately 2.7 kHz, safe operation of the stack using the integrated cooling system was proven both by simulation as well as by experiments. For cutting plates out of stainless steel with a thickness of 10 mm an increase of the cutting speed by 60% was achieved compared to conventional processes at unchanged cut edge quality. The great importance of laser machining processes and the need of further improvement of these applications has been considered through development of the presented highly dynamic focus shifting module.
Keywords: Laser beam, piezo, shaping, thermal control, optics, full-stroke, focal