Dr. Uwe Griebner
uwe.griebner(at)mbi-berlin.de
+49 30 6392 1457
C2: Solid State Light Sources
Haus C, 2.22

Position
Project Coordinator 4.1: Implementation of Lasers and Measuring Techniques
Research
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).
Curriculum vitae
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,
MBI Publikationen
- Pulse shaping in a midwave-IR OPCPA for multi-μJ few-cycle pulse generation at 12 μm via DFG Optics Express 31 (2023) 14096-14108
- 44-fs pulse generation at 2.05 µm from a SESAM mode-locked Tm:GdScO3 laser Optics Letters 48 (2023) 510-513
- Tm,Ho:Ca(Gd,Lu)AlO4 crystals: Polarized spectroscopy and laser operation Journal of Luminescence 257 (2023) 119638/1-11
- Excitation transfer from Cr2+ to Fe2+ ions in co-doped ZnSe as a pumping scheme for infrared solid-state lasers Journal of Electronic Materials Online (2023)
- Efficient electronic excitation transfer via phonon-assisted dipole-dipole coupling in Fe2+∶Cr2+:ZnSe Physical Review Applied 19 (2023) 054043/1-11
- Tm,Ho:Ca(Gd,Lu)AlO4 crystals: Crystal growth, structure refinement and Judd-Ofelt analysis Journal of Luminescence 246 (2022) 118828/1-10
- Diode-pumped and tunable laser operation of Tm,Ho-codoped modified CNGG-type disordered crystals Proceedings of SPIE 11980 (2022) 198003/1-6
- Sub-100 fs SWCNT-SA mode-locked Tm,Ho:LCLNGG laser Proceedings of SPIE 11980 (2022) 1198002/1-6
- Cr:ZnS-based soliton self-frequency shifted signal generation for a tunable sub-100 fs MWIR OPCPA Optics Express 30 (2022) 5142-5150
- Kinetics of excitation transfer from Cr2+ to Fe2+ ions in co-doped ZnSe Optics Letters 47 (2022) 2129-2131