Within a project funded by the German Ministry for Education and Research (BMBF) a multi-pass thin-disk laser amplifier generating record output powers was demonstrated at the IFSW in collaboration with Trumpf Laser GmbH.
The realized system delivered ultrashort laser pulses with an average output power of 1.4 kW in the infrared (1030 nm). The emitted pulses were 8 ps long at a pulse repetition rate of 300 kHz (4.7 mJ pulse energy) and with a beam quality factor being smaller than M²=1.4. To achieve this, a commercial TruMicro5050 (115 W output power, 6.5 ps pulse duration) was used as seed source. Its beam is amplified by folding it 40 times over a thin-disk laser crystal using an array of 40 mirrors. This system is the first demonstration of a thin-disk laser delivering ultrashort laser pulses with more than 1 kW output power. Furthermore, the pulse peak power is very high in comparison to other laser systems with output powers in the kW-range. This combination will allow a very high productivity for ultra-precise laser materials processing, e.g. cutting of carbon-fiber-reinforced-plastics (CFRP). Additionally, an average power of 820 W in the green spectral region and 234 W in the UV were demonstrated by frequency conversion of the IR beam. These are the highest output powers reported so far for ultrafast lasers at these wavelengths.
Further details can be found in J. Negel et al., "Ultrafast thin-disk multipass laser amplifier delivering 1.4 kW (4.7 mJ, 1030 nm) average power converted to 820 W at 515 nm and 234 W at 343 nm," Opt. Express 23, 21064-21077 (2015).
Contact: Dr. Marwan Abdou Ahmed