Project Coordinator 4.1: Implementation of Lasers and Measuring Techniques
Development of advanced ultrashort pulse lasers, amplifiers, and parametric devices operating in the near- and mid-IR wavelength ranges including components and complete systems for direct implementation within other projects at MBI.
An example is the development of novel CPA laser sources emitting around 2 µm wavelength. This laser system operating at kilohertz repetition rate will serve as driver for OPCPA in the mid-IR. Figure (a) shows the simulated bifurcation diagram of a Ho:YLF regenerative amplifier (RA) at a 1 kHz repetition rate and 24 round trips indicating the most interesting operation regimes, i.e., stable double-pulsing (yellow coded bar) and the single-energy regime (green coded bar) beyond the final bifurcation point (BP final). Based on our model the RA is designed for operation in the single-energy regime beyond BPfinal. The measured complete RA bifurcation diagram of the re-designed RA at 1 kHz and 24 round trips is presented in Fig. (b). It agrees well with our numerical simulations [Fig. (a)]. Only the predicted multi-pulsing between 20 and 30 W pump power is less pronounced in the experiment. The highest pulse energy of 12 mJ can be extracted in the stable double-pulsing regime in the upper bifurcation branch (yellow coded bar), however at 0.5 kHz, the half of the repetition rate. BPfinal appears at a pump power of 47 W and denotes the transition to the single-energy regime where any multi-stabilities and chaotic behavior have been overcome. The extracted RA pulse energy of 9.7 mJ is the by far highest reported for 2-µm RAs operating in the single-energy regime. Taking into account the applied pump power of 50 W, the extraction efficiency is as high as 19.5%. Performing the transition from the stable double-pulsing to the single-energy regime, the RA’s pulse-to-pulse stability is further improved with a rms value <0.5%. Figure (c) shows the corresponding pulse stability measurement in the vicinity of BPfinal and beyond in the single-energy regime (green coded bar).
since 1992 Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Berlin, Germany, staff scientist and project coordinator.
1993 - 1996 Ph.D. thesis at the Optical Institute, Technical University Berlin, Germany, with Prof. Horst Weber,
Title of thesis: Fiber bundle lasers with high average power,
1989 - 1992 Institute of Nonlinear Optics and Short Pulse Spectroscopy, Berlin, Germany, staff scientist,
1986 - 1989 Institute of Mechanics, Chemnitz, Germany, staff scientist,
1981 - 1986 Diploma degree in Physics; Physics Department, University of Jena, Germany,
Title of thesis: Characterization of lattice distorsions in LiF crystals,
- Passive Q switching of Yb:CNGS lasers by Cr4+:YAG and V3+:YAG saturable absorbers Applied Optics 57 (2018) 8236-8241
- Oriented zinc oxide nanorods: A novel saturable absorber for lasers in the near-infrared Beilstein Journal of Nanotechnology 9 (2018) 2730–2740
- Sub-80 fs mode-locked Tm,Ho-codoped disordered garnet crystal oscillator operating at 2081 nm Optics Letters 43 (2018) 5154-5157
- Passively Q-switched femtosecond-laser-written thulium waveguide laser based on evanescent field interaction with carbon nanotubes Photonics Research 6 (2018) 971-980
- Highly-efficient Ho:KY(WO4)2 thin-disk lasers at 2.06 µm SPIE Proceedings Series 10713 (2018) 107130J/1-8
- Generation of millijoule few-cycle pulses at 5 μm by indirect spectral shaping of the idler in an optical parametric chirped pulse amplifier Journal of the Optical Society of America B-Optical Physics 35 (2018) C18-C24
- Modelling of graphene Q-switched Tm lasers Optics Communications 389 (2017) 15-22
- Indium-modified Yb:KLu(WO4)2 crystal: Growth, spectroscopy and laser operation Journal of Luminescence 183 (2017) 391-400
- Crystal growth, optical spectroscopy and laser action of Tm3+-doped monoclinic magnesium tungstate Optics Express 25 (2017) 3682-3693
- Comparative spectroscopic and thermo-optic study of Tm:LiLnF4 (Ln = Y, Gd, and Lu) crystals for highly-efficient microchip lasers at ~2 μm Optical Materials Express 7 (2017) 844-854