Stuttgart, Germany

Dausinger + Giesen GmbH

www.dausinger-giesen.de/
Stuttgart, Germany
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Neuhaus J.,Dausinger + Giesen GmbH | Fink F.,Dausinger + Giesen GmbH | Hehl G.,Dausinger + Giesen GmbH | Larionov M.,Dausinger + Giesen GmbH | And 2 more authors.
Optics InfoBase Conference Papers | Year: 2017

We present experimental and theoretical results for parallel amplification of 350 fs and 2.7 ps in the same Yb:YAG regenerative thin-disk amplifier for high energy OPCPA pumping and stable supercontinuum generation for OPCPA seeding. © OSA 2017.


Neuhaus J.,Dausinger + Giesen GmbH | Fink F.,Dausinger + Giesen GmbH | Larionov M.,Dausinger + Giesen GmbH
Journal of the Optical Society of America B: Optical Physics | Year: 2017

As a result of experimentally verified simulations of Yb:YAG regenerative amplifiers utilizing spectral broadening effects due to self-phase modulation, we provide a map for the optimized choice of initial chirp and internal group-delay dispersion (GDD) within the amplifier. We show that the shortest pulse durations can be obtained with negative internal GDD, being, however, limited by the damage threshold of the optical components due to increased peak powers and by a breakup of pulses comparable to the propagation of higher-order solitons. We propose that by usage of increasing amounts of positive internal GDD, along with a corresponding amount of negative initial GDD, the obtainable peak powers after compression can be scaled far beyond the usual gain-bandwidth limitation. © 2017 Optical Society of America.


PubMed | Dausinger + Giesen GmbH, University of Stuttgart, University of Coimbra, ETH Zurich and 9 more.
Type: Journal Article | Journal: Science (New York, N.Y.) | Year: 2016

The deuteron is the simplest compound nucleus, composed of one proton and one neutron. Deuteron properties such as the root-mean-square charge radius rd and the polarizability serve as important benchmarks for understanding the nuclear forces and structure. Muonic deuterium d is the exotic atom formed by a deuteron and a negative muon (-). We measured three 2S-2P transitions in d and obtain r(d) = 2.12562(78) fm, which is 2.7 times more accurate but 7.5 smaller than the CODATA-2010 value r(d) = 2.1424(21) fm. The d value is also 3.5 smaller than the r(d) value from electronic deuterium spectroscopy. The smaller r(d), when combined with the electronic isotope shift, yields a small proton radius r(p), similar to the one from muonic hydrogen, amplifying the proton radius puzzle.


Zhang D.,University of Duisburg - Essen | Gokce B.,University of Duisburg - Essen | Sommer S.,Dausinger + Giesen GmbH | Streubel R.,University of Duisburg - Essen | Barcikowski S.,University of Duisburg - Essen
Applied Surface Science | Year: 2016

In this paper, we perform liquid-assisted picosecond laser cutting of 150 μm thin germanium wafers from the rear side. By investigating the cutting efficiency (the ability to allow an one-line cut-through) and quality (characterized by groove morphologies on both sides), the pros and cons of this technique under different conditions are clarified. Specifically, with laser fluence fixed, repetition rate and scanning speed are varied to show quality and efficiency control by means of laser parameter modulation. It is found that low repetition rate ablation in liquid gives rise to a better cut quality on the front side than high repetition rate ablation since it avoids dispersed nanoparticles redeposition resulting from a bubble collapse, unlike the case of 100 kHz which leads to large nanorings near the grooves resulting from a strong interaction of bubbles and the case of 50 kHz which leads to random cutting due to the interaction of the former pulse induced cavitation bubble and the subsequent laser pulse. Furthermore, ethanol is mixed with pure distilled water to assess the liquid's impact on the cutting efficiency and cutting quality. The results show that increasing the ethanol fraction decreases the ablation efficiency but simultaneously, greatly improves the cutting quality. The improvement of cut quality as ethanol ratio increases may be attributed to less laser beam interference by a lower density of bubbles which adhere near the cut kerf during ablation. A higher density of bubbles generated from ethanol vaporization during laser ablation in liquid will cause stronger bubble shielding effect toward the laser beam propagation and therefore result in less laser energy available for the cut, which is the main reason for the decrease of cut efficiency in water-ethanol mixtures. Our findings give an insight into under which condition the rear-side laser cutting of thin solar cells should be performed: high repetition, pure distilled water and high laser power are favorable for high-speed rough cutting but the cut kerf suffers from strong side effects of ripples, nanoredeposition occurrence, while low laser power at low repetition rate (10 kHz), mixed solution (1 wt% ethanol in water) and moderate scanning speed (100 μm/s) are preferable for ultrafine high-quality debris-free cutting. The feasibility of high-quality cut is a good indication of using rear laser ablation in liquid to cut thinner wafers. More importantly, this technique spares any post cleaning steps to reduce the risk to the contamination or crack of the thin wafers. © 2016 Elsevier B.V. All rights reserved.


Kononenko T.V.,RAS A.M. Prokhorov General Physics Institute | Schoneseiffen S.,Dausinger + Giesen GmbH | Konov V.I.,RAS A.M. Prokhorov General Physics Institute | Dausinger F.,Dausinger + Giesen GmbH
Quantum Electronics | Year: 2013

The thresholds of optical breakdown in the volume of quartz glass were measured in relation to the number of pulses under irradiation by ultrashort laser pulses with different pulse repetition frequencies (1 - 400 kHz). Increasing this frequency from 10 to 400 kHz was found to substantially lower the breakdown threshold for 500-fs long pulses (at a wavelength of 1030 nm) and to lower to a smaller degree for 5-ps long pulses (515 nm). A strong frequency dependence of the breakdown threshold is observed under the same conditions as a manifold decrease of the breakdown threshold with increase in the number of pulses in a pulse train. The dependence of the optical breakdown on the number of pulses is attributable to the accumulation of point defects under multiple subthreshold irradiation, which affects the mechanism of collisional ionisation. In this case, the frequency dependence of the breakdown threshold of quartz glass is determined by the engagement of shortlived defects in the ionisation mechanism. © 2013 Kvantovaya Elektronika and Turpion Ltd.


Schuhmann K.,ETH Zurich | Larionov M.,Dausinger + Giesen GmbH
Optics InfoBase Conference Papers | Year: 2013

A frequency-doubled single-frequency disk laser demonstrates 30 W output at an efficiency of 30 % using a VBG with 4 % loss in a coupled cavity, reducing its thermal load and loss. © OSA 2013.


Borchers B.,Coherent GmbH | Schafer C.,Coherent GmbH | Fries C.,Photonik Zentrum Kaiserslautern E.V. | Larionov M.,Dausinger + Giesen GmbH | Knappe R.,Coherent GmbH
Advanced Solid State Lasers, ASSL 2015 | Year: 2015

We present a novel two-crystal approach rendering polarization rotation mode-locking via cascaded χ2-nonlinearities applicable to broadband lasers sources. This technique is demonstrated at a thin disk oscillator reaching >40W average power and <500fs pulse duration. © OSA 2015.


Dausingera F.,Dausinger + Giesen GmbH | Larionov M.,Dausinger + Giesen GmbH
Physics Procedia | Year: 2010

Since many years shortening of pulse duration down to femtosecond regime is propagated as a recipe for achieving higher precision in micro machining with lasers. The drawback of this approach is a loss in productivity which cannot be accepted when large work pieces such as rolls, cylinder liners or solar panels have to be treated. A novel development tool based on disk technology will be presented allowing finding application specific highest productivity at still acceptable inaccuracy.


Larionov M.,Dausinger + Giesen GmbH | Neuhaus J.,Dausinger + Giesen GmbH
Advanced Solid State Lasers, ASSL 2014 | Year: 2014

A regenerative thin disk laser amplifier generating nanosecond pulses with an average power of 120 W at a repetition rate of 1 kHz with a nearly diffraction limited beam is presented. © OSA 2014.


Sommer S.,Dausinger + Giesen GmbH | Dausinger F.,Dausinger + Giesen GmbH
30th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2011 | Year: 2011

New dimensions in precision and the variety of machinable materials are enabled by the use of ultrashort laser pulses in material processing. Due to new powerful beam sources the processing efficiency has already reached an economic interesting state. Based on a regenerative disc amplifier the Dausinger + Giesen GmbH has developed a femtosecond source that is distinguished on its high flexibility and high pulse energy. Out of one resonator pulses with durations from 400 fs up to 1 μs can be emitted. The high repetition rate of up to 1 MHz at an average power of 50 W makes this system very attractive for processing development, because different available systems can be simulated in only one setup. The large variety in material processing from precision drilling, over volume ablation in different materials up to the structuring in thin films could be demonstrated over several pulse durations and even in hybrid processes.

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