Voici les éléments 1 - 10 sur 87
- PublicationMétadonnées seulementHighly efficient optically pumped vertical-emitting semiconductor laser with more than 20 W average output power in a fundamental transverse mode
- PublicationMétadonnées seulementFemtosecond diode-pumped solid-state laser with a repetition rate of 4.8 GHz(2012)
;Pekarek, Selina ;Klenner, Alexander ; ;Fiebig, Christian ;Paschke, Katrin ;Erbert, GötzKeller, Ursula
- PublicationMétadonnées seulementDiode-pumped gigahertz femtosecond Yb: KGW laser with a peak power of 3.9 kW(2010)
;Pekarek, Selina ;Fiebig, Christian ;Stumpf, Max ;Oehler, Andreas Ernst Heinz ;Paschke, Katrin ;Erbert, Götz ;Keller, Ursula
- PublicationMétadonnées seulementVertical integration of ultrafast semiconductor lasers(2007)
;Maas, Deran J. H. C. ;Bellancourt, Aude-Reine ;Rudin, Benjamin ;Golling, Matthias ;Unold, HJ ;Keller, Ursula
- PublicationAccès libreCarrier-envelope offset frequency stabilization of a gigahertz semiconductor disk laserOptical frequency combs based on ultrafast lasers have enabled numerous scientific breakthroughs. However, their use for commercial applications is limited by the complexity and cost of femtosecond laser technology. Ultrafast semiconductor lasers might change this issue as they can be mass produced in a cost-efficient way while providing large spectral coverage from a single technology. However, it has not been proven to date if ultrafast semiconductor lasers are suitable for stabilization of their carrier-envelope offset (CEO) frequency. Here we present what we believe to be the first CEO frequency stabilization of an ultrafast semiconductor disk laser (SDL). The optically pumped SDL is passively modelocked by a semiconductor saturable absorber mirror. It operates at a repetition rate of 1.8 GHz and a center wavelength of 1034 nm. The 273 fs pulses of the oscillator are amplified to an average power level of 6 W and temporally compressed down to 120 fs. A coherent octave-spanning supercontinuum spectrum is generated in a photonic crystal fiber. The CEO frequency is detected in a standard ƒ–to–2ƒ interferometer and phase locked to an external reference by feedback applied to the current of the SDL pump diode. This proof-of-principle demonstrates that ultrafast SDLs are suitable for CEO stabilization and constitutes a key step for further developments of this comb technology expected in the coming years.
- PublicationMétadonnées seulementPicosecond diode-pumped 1.5 ?m Er, Yb: glass lasers operating atá10?100 GHz repetition rate(2010)
;Oehler, Andreas Ernst Heinz ;Stumpf, Max ;Pekarek, Selina ; ;Weingarten, Kurt JKeller, Ursula
- PublicationAccès libreExtreme ultraviolet light source at a megahertz repetition rate based on high-harmonic generation inside a mode-locked thin-disk laser oscillatorWe demonstrate a compact extreme ultraviolet (XUV) source based on high-harmonic generation (HHG) driven directly inside the cavity of a mode-locked thin-disk laser oscillator. The laser is directly diode-pumped at a power of only 51 W and operates at a wavelength of 1034 nm and a 17.35 MHz repetition rate. We drive HHG in a high-pressure xenon gas jet with an intracavity peak intensity of 2.8×1013 W/cm2 and 320 W of intracavity average power. Despite the high-pressure gas jet, the laser operates at high stability. We detect harmonics up to the 17th order (60.8 nm, 20.4 eV) and estimate a flux of 2.6×108 photons/s for the 11th harmonic (94 nm, 13.2 eV). Due to the power scalability of the thin-disk concept, this class of compact XUV sources has the potential to become a versatile tool for areas such as attosecond science, XUV spectroscopy, and high-resolution imaging.
- PublicationAccès libreGigahertz frequency comb from a diode-pumped solid-state laserWe present the first stabilization of the frequency comb offset from a diode-pumped gigahertz solid-state laser oscillator. No additional external amplification and/or compression of the output pulses is required. The laser is reliably modelocked using a SESAM and is based on a diode-pumped Yb:CALGO gain crystal. It generates 1.7-W average output power and pulse durations as short as 64 fs at a pulse repetition rate of 1 GHz. We generate an octave-spanning supercontinuum in a highly nonlinear fiber and use the standard ƒ-to-2ƒ carrier-envelope offset (CEO) frequency ƒCEO detection method. As a pump source, we use a reliable and cost-efficient commercial diode laser. Its multi-spatial-mode beam profile leads to a relatively broad frequency comb offset beat signal, which nevertheless can be phase-locked by feedback to its current. Using improved electronics, we reached a feedback-loop-bandwidth of up to 300 kHz. A combination of digital and analog electronics is used to achieve a tight phase-lock of ƒCEO to an external microwave reference with a low in-loop residual integrated phase-noise of 744 mrad in an integration bandwidth of [1 Hz, 5 MHz]. An analysis of the laser noise and response functions is presented which gives detailed insights into the CEO stabilization of this frequency comb.
- PublicationMétadonnées seulement60-W average power in 810-fs pulses from a thin-disk Yb: YAG laser(: Optical Society of America, 2003)
;Innerhofer, Edith ; ;Brunner, Felix ;Häring, R ;Aschwanden, A ;Paschotta, Rüdiger ;Hönninger, C ;Kumkar, MKeller, Ursula
- PublicationAccès libreUltrafast thin-disk laser with 80 µJ pulse energy and 242 W of average powerWe present a semiconductor saturable absorber mirror (SESAM) mode-locked thin-disk laser generating 80 µJ of pulse energy without additional amplification. This laser oscillator operates at a repetition rate of 3.03 MHz and delivers up to 242 W of average output power with a pulse duration of 1.07 ps, resulting in an output peak power of 66 MW. In order to minimize the parasitic nonlinearity of the air inside the laser cavity, the oscillator was operated in a vacuum environment. To start and stabilize soliton mode locking, we used an optimized high-damage threshold, low-loss SESAM. With this new milestone result, we have successfully scaled the pulse energy of ultrafast laser oscillators to a new performance regime and can predict that pulse energies of several hundreds of microjoules will become possible in the near future. Such lasers are interesting for both industrial and scientific applications, for example for precise micromachining and attosecond science.