A new multipass amplifier was developed at the IFSW which emits laser pulses with 400 W of average power and 2 GW of peak power .
The pulse duration was measured to be 885 fs at a repetition rate of 200 kHz and with linear polarization. This is the highest output power for GW-level laser pulses from a multipass amplifier. The system was realized within the EU-project “RAZipol” in collaboration with the “Schweißtechnische Lehr-und Versuchsanstalt Mecklenburg-Vorpommern”. The employed seed source was a TruMicro Femto Edition with 40 W of average power, 200 kHz repetition rate and 805 fs pulse duration.
In a further experiment, radially polarized laser pulses were amplified. Here, a maximum output power of 235 W at a pulse duration of 888 fs was achieved. This is the highest output power for radially polarized GW-level pulses.
The achieved results are a major milestone for scaling the output power of ultrafast multipass amplifiers to the kW-level, GW-level peak powers and pulse durations at the fs-level. Furthermore, the results pave the way for experiments on pulse compression to further reduce the pulse duration.
Contact: Dr. Marwan Abdou Ahmed
 J. Negel et al., "Thin-disk multipass amplifier for fs pulses delivering 400 W of average and 2.0 GW of peak power for linear polarization as well as 235 W and 1.2 GW for radial polarization," Appl. Phys B. 123, 156 (2017).