@article{WittrockVorholt2015, author = {Wittrock, Ulrich and Vorholt, Christian}, title = {Spatial hole burning in Yb:YAG thin-disk lasers}, series = {Appl. Phys. B}, volume = {120}, journal = {Appl. Phys. B}, doi = {10.25974/fhms-823}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-8234}, pages = {711 -- 721}, year = {2015}, abstract = {The spatially varying intensity in a standing wave resonator leads to spatial hole burning in the gain medium of a laser. The spatial hole burning changes the gain of different longitudinal modes and can thus determine the optical spectrum of the laser. We simulate this longitudinal mode competition in standing wave resonators of thin-disk lasers. The resulting optical spectra of the laser are compared to measured optical spectra. We examine two types of resonators: I-resonators and V-resonators with different angles of incidence. In V-resonators, the non-normal incidence of the laser beam on the disk lifts the degeneracy of the polarization. Experiments show that the slight gain advantage for the p-polarization does not lead to polarized emission. For both types of resonators, the measured spectra are in good agreement with the simulated ones. The simulations allow to study the influence of spectral intra-cavity losses on the optical spectrum of a thin-disk laser.}, language = {en} } @article{VorholtWittrock2015, author = {Vorholt, Christian and Wittrock, Ulrich}, title = {Intra-cavity pumped Yb:YAG thin-disk laser with 1.74\% quantum defect}, series = {Opt. Lett.}, volume = {40}, journal = {Opt. Lett.}, doi = {10.25974/fhms-828}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-8284}, pages = {4819 -- 4822}, year = {2015}, abstract = {We present, to the best of our knowledge, the first intracavity pumped Yb:YAG thin-disk laser. It operates at 1050.7 nm with a quantum defect of just 1.74\% due to pumping at 1032.4 nm. Low absorption of the pump light at the pump wavelength of 1032.4 nm is compensated for by placing the disk inside the resonator of another Yb:YAG thin-disk laser which is diode-pumped at 940 nm. The intra-cavity pumped laser has an output power of 10.3 W and a slope efficiency of 8.3\%}, language = {en} } @inproceedings{VorholtWittrock2015, author = {Vorholt, Christian and Wittrock, Ulrich}, title = {Wavelength control by angle-tuning of the laser radiation in an intra-cavity pumped Yb:YAG thin-disk laser}, series = {Advanced Solid State Lasers (ASSL), paper AM5A.39}, booktitle = {Advanced Solid State Lasers (ASSL), paper AM5A.39}, doi = {10.25974/fhms-829}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-8298}, year = {2015}, abstract = {In an intra-cavity pumped thin-disk laser the pump radiation forms a standing wave pattern inside the intra-cavity pumped disk.We demonstrate experimentally that the grating period of the standing wave pattern of the pump radiation can control the laser wavelength.}, language = {en} } @article{VorholtWittrock2017, author = {Vorholt, Christian and Wittrock, Ulrich}, title = {Single-frequency oscillation of thin-disk lasers due to phase-matched pumping}, series = {Opt. Expr.}, volume = {25}, journal = {Opt. Expr.}, doi = {10.25974/fhms-1025}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-10258}, pages = {21388 -- 21399}, year = {2017}, abstract = {We present a novel pump concept that should lead to single-frequency operation of thin-disk lasers without the need for etalons or other spectral filters. The single-frequency operation is due to matching the standing wave pattern of partially coherent pump light to the standing wave pattern of the laser light inside the disk. The output power and the optical efficiency of our novel pump concept are compared with conventional pumping. The feasibility of our pump concept was shown in previous experiments.}, language = {en} } @article{TrinschekVorholtWittrock2021, author = {Trinschek, Sarah and Vorholt, Christian and Wittrock, Ulrich}, title = {Nonlinear dynamics in intra-cavity pumped thin-disk lasers}, series = {Optics Express}, volume = {29}, journal = {Optics Express}, number = {4}, doi = {https://doi.org/10.1364/OE.417154}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-132355}, pages = {5755 -- 5773}, year = {2021}, abstract = {Cross-saturation of the gain media in intra-cavity pumped lasers leads to complex dynamics of the laser power. We present experimental results and a detailed theoretical analysis of this nonlinear dynamics for an intra-cavity pumped Yb:YAG thin-disk laser in the framework of a rate-equation model. The gain medium of this laser is residing in the resonator of a conventional, diode-pumped Yb:YAG thin-disk laser. Continuous-wave operation, periodic pulse trains, and chaotic fluctuations of the optical power of both lasers were observed. The dynamics is not driven by external perturbations but arises naturally in this laser system. Further examination revealed that these modes of operation can be controlled by the resonator length of the diode-pumped laser but that the system can also show hysteresis and multi-stability.}, language = {en} }