@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}
}
@article{PuesLaubeFischeretal.2021,
  author    = {Pues, Patrick and Laube, Michael and Fischer, Stefan and Schr{\"o}der, Franziska and Schwung, Sebastian and Rytz, Daniel and Fiehler, Torben and Wittrock, Ulrich and J{\"u}stel, Thomas},
  title     = {Luminescence and up-conversion of single crystalline Lu3Al5O12:Pr3+},
  series = {Journal of Luminescence},
  volume    = {234},
  journal   = {Journal of Luminescence},
  doi       = {10.1016/j.jlumin.2021.117987},
  pages     = {117987 -- 117995},
  year      = {2021},
  abstract  = {This work deals with the spectroscopic properties of praseodymium doped single crystalline lutetium aluminum garnet (LuAG:Pr3+). A special focus was set on temperature- and time-dependent spectroscopy. Beyond the well-known down-conversion luminescence of LuAG:Pr3+, also UV-A/B up-conversion luminescence under excitation with a 488 nm laser was thoroughly investigated. Furthermore, the results of the spectroscopic investigations on the single crystalline material were supplemented and compared with measurements on a microscale powder sample. In addition, to the spectroscopic investigations, mechanistic considerations are presented to obtain a closer look at the up-conversion process in LuAG:Pr3+. We promote the thesis of a temperature-dependent energy transfer up-conversion mechanism.},
  language  = {en}
}