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
- Mode-locked Tm,Ho:KLu(WO4)2 laser at 2060 nm using InGaSb-based SESAMs Optics Express 23 (2015) 4614-4619
- GaSb-based SESAM mode-locked Tm:YAG ceramic laser at 2 µm Optics Express 23 (2015) 1361-1369
- High-energy multi-kilohertz Ho-doped regenerative amplifiers around 2 µm Optics Express 23 (2015) 14744-14752
- Picosecond 34 mJ pulses at kHz repetition rates from a Ho:YLF amplifier at 2 μm wavelength Optics Express 23 (2015) 33142-33149
- Graphene Q-switched Yb:KYW planar waveguide laser AIP Advances 5 (2015) 017110/1-6
- Tm:KLu(WO4)2 microchip laser Q-switched by a graphene-based saturable absorber Optics Express 23 (2015) 14108-14113
- Single-layer graphene saturable absorber for diode-pumped passively Q-switched Tm:KLu(WO4)2 laser at 2 µm Laser Physics Letters 12 (2015) 095802/1-5
- Diode-pumped SESAM mode-locked Yb:CLNGG laser Optics and Laser Technology 69 (2015) 144-147
- In-band-pumped Ho:KLu(WO4)2 microchip laser with 84% slope efficiency Optics Letters 40 (2015) 344-347
- Ho:KLuW microchip laser intracavity-pumped by a diode-pumped Tm:KLuW laser Applied Physics B 120 (2015) 123-128