High-power high-brightness disk lasers for advanced applications

Abstract

We report technological advances in thin-disk laser technology enabling further scaling of average output power and beam quality. A newly developed resonator design serves as a universal building block for industrial-grade thin-disk lasers from 6 to 24 kW. The robust resonator design allows for power levels beyond 12 kW from a single disk with a beam parameter product (BPP) of ~ 4 mm*mrad. By polarization combining of the output of two resonators, i.e. two laser disks, the power can be doubled to up to 24 kW while maintaining the good beam quality. The mentioned properties render the new TruDisk lasers ideal for high-throughput laser material processing. With slight modifications of our setup we also achieve a BPP of ~ 2 mm*mrad with < 8 kW output power. The optical setup provides two fiber outputs, switchable on a < 100 ms timescale, that can be equipped with different types of exchangeable processing fibers for maximum productivity and flexibility. It is possible to use TRUMPF’s BrightLine Weld (BLW) technology in combination with a 50/200 µm dual-core fiber at each fiber port. The BLW technology allows for distribution of the laser power between the 50 µm fiber core and a 200 µm ring, enabling a significant increase in productivity and quality in welding. We use BLW with a 50/200 µm dual-core fiber for welding of stator hairpins for electric drives at a quality and speed unattained so far.