Product Code: ICA11_1001

Drilling with Fiber Lasers
Authors:
Jens Dietrich, Lehrstuhl fuer Lasertechnik; 52074 Aachen Germany
Christoph Blaesius, Lehrstuhl fuer Lasertechnik; 52074 Aachen Germany
Stefan Brief, Lehrstuhl fuer Lasertechnik; 52074 Aachen Germany
Ingomar Kelbassa, Lehrstuhl fuer Lasertechnik; 52074 Aachen Germany
Presented at ICALEO 2011

For drilling holes such as cooling holes in turbine blades with diameters from 100 µm up to 1.5 mm flash lamp pumped laser sources e.g. slab lasers are commonly used. These laser sources have peak powers of several kW at pulse durations from microseconds up to milliseconds with a high beam quality. Due to the beam quality, small spot sizes and intensities greater than 106 W/cm2 are achieved. The average power of these laser sources is in the range of a few mW up to several hundred W rather small.
So far fiber lasers are not used for laser drilling due to small peak powers and intensities. Meanwhile, fiber laser with a scalable output power of 1 W up to 50 kW in multimode or up to 10 kW in single-mode with a beam quality of M² < 6 in the multimode and M² < 1,07 in single-mode are offered. With these fiber lasers drilling seems to be possible. Thus laser drilling with fiber lasers is investigated and compared to flash lamp pumped Nd:YAG lasers.