PFS-Pro is a state of the art Yb:YAG laser system that provides a unique combination of average power, pulse energy and pulse duration and will be the driving laser for new high repetition rate X-ray sources. It tackles the challenge of third generation laser systems to provide pulses with multi-terawatt peak powers and kilohertz repetition rate using established thin-disk technology and a novel nonlinear broadening scheme. Figure 1 gives an impression of the system in the laboratory.
Figure 1: Laser overview
PFS-Pro consists of a chirped pulse amplifier that increases the pulse energy of a commercial fiber laser by a factor of more than 30 million. To this end the pulses originating from the fiber oscillator are stretched in time and coupled into a thin-disk regenerative amplifier (see the block diagram in figure 2) to finally obtain an output energy of more than 100 mJ with a kHz-scale repetition rate. Two 4 kW 969nm diode laser stacks provide the pump power for the thin-disks making this amplifier one of the strongest amplifiers of its kind. For more details please refer to our publication .
The pulses originating from the amplifier system are then recompressed in time by a grating compressor to a pulse duration of about 1.3 ps. To further shorten the pulse duration, a novel nonlinear broadening concept based on multipass cells was adapted for high energy pulses .
Figure 2: PFS-Pro Optical Setup
In the multipass cell used for PFS-Pro, more than 100 mJ of pulse energy is spectrally broadened in an argon atmosphere to support pulse durations below 40 fs . With a length of 9 m and with a mirror distance of about 8 m, this multipass cell is among the largest multipass systems for nonlinear spectral broadening worldwide and enables unprecedented throughput energies. PFS-Pro is complemented by an additional thin-disk booster system. The booster is currently under development and expected to provide picosecond pulses with several hundred millijoules of pulse energy. A more complete description of PFS-Pro can also be found in the PhD-thesis .
- Thomas Nubbemeyer, Martin Kaumanns, Moritz Ueffing, Martin Gorjan, Ayman Alismail, Hanieh Fattahi, Jonathan Brons, Oleg Pronin, Helena G. Barros, Zsuzsanna Major, Thomas Metzger, Dirk Sutter, and Ferenc Krausz, "1 kW, 200 mJ picosecond thin-disk laser system," Opt. Lett. 42, 1381-1384 (2017)
- Martin Kaumanns, Vladimir Pervak, Dmitrii Kormin, Vyacheslav Leshchenko, Alexander Kessel, Moritz Ueffing, Yu Chen, and Thomas Nubbemeyer, "Multipass spectral broadening of 18 mJ pulses compressible from 1.3 ps to 41 fs," Opt. Lett. 43, 5877-5880 (2018)
- Martin Kaumanns, Dmitrii Kormin, Thomas Nubbemeyer, Vladimir Pervak, and Stefan Karsch, "Spectral broadening of 112 mJ, 1.3 ps pulses at 5 kHz in a LG10 multipass cell with compressibility to 37 fs," Opt. Lett. 46, 929-932 (2021)
- Kaumanns, Reimund Martin (2020): Generation of energetic femtosecond pulses at high average power. Dissertation, LMU München: Faculty of Physics
Project coordinator: Stefan Karsch