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
- Thermal lensing and multiwatt microchip laser operation of Yb:YCOB crystals IEEE Photonics Journal 8 (2016) 1501312/1-12
- Taming chaos: 16 mJ picosecond Ho:YLF regenerative amplifier with 0.7 kHz repetition rate Laser & Photonics Reviews 10 (2016) 123–130
- Ho:YLF chirped pulse amplification at kilohertz repetition rates – 4.3 ps pulses at 2 μm with GW peak power Optics Letters 41 (2016) 4668-4671
- Femtosecond mode-locked semiconductor disk laser Ultrashort Pulse Laser Technology Springer (2016) 47-74
- Broadly tunable mode-locked Ho:YAG ceramic laser around 2.1 µm Optics Express 24 (2016) 18003-18012
- Q-switching of Yb:YGG, Yb:LuGG and Yb:CNGG lasers by a graphene saturable absorber Optical and Quantum Electronics 48 (2016) 197/1-7
- Microchip laser operation of Yb-doped gallium garnets Optical Materials Express 6 (2016) 46-57
- SESAM mode-locked Tm:CALGO laser at 2 mm Optical Materials Express 6 (2016) 131-136
- Q-switching of Tm,Ho:KLu(WO4)2 microchip laser by a graphene-based saturable absorber Laser Physics Letters 13 (2016) 025801/1-5
- Spectroscopic and laser characterization of Yb,Tm:KLu(WO4)2 crystal Optical Materials 51 (2016) 223-231