Product Code: ICAL08_206

The Relevance of Brightness for High Power Laser Cutting and Welding
Authors:
Dirk Petring, Fraunhofer ILT; Aachen Germany
Frank Schneider, Fraunhofer ILT; Aachen Germany
Norbert Wolf, Fraunhofer ILT; Aachen Germany
Vahid Nazery, Fraunhofer ILT; Aachen Germany
Presented at ICALEO 2008

Is there an optimum brightness regime for macro laser processing of materials? Does increased brightness always improve productivity? These questions have been vigorously discussed since lasers offering beam properties near to the theoretical diffraction limit in the multi-kW range have become available. As a contribution to this debate this paper begins by describing the brightness map of modern industrial laser types. Following this, the theoretical consequences of various brightness levels on the physics of the interaction zone and on achievable speed and maximum sheet thickness are evaluated. Finally the practical impact of brightness on the cutting and welding capabilities of laser systems is demonstrated by means of various experimental results with fiber and disk lasers up to 8 kW.