Jan. 1991 - May 1992: research associate, Center for Advanced Studies, University of New Mexico, Albuquerque, U.S.A.
May 1992 - Sept. 2000: wissenschaftlicher Assistent, LMU München, Germany
March 1996 - Apr. 1997: Feodor-Lynen Fellow of the Alexander von Humboldt Foundation at Texas A & M University, College Station, U.S.A.
Sept. - Nov. 1997: visit to Dept. of Physics, University of Auckland, Auckland, New Zealand
March - May 1999: visit to ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, U.S.A.
May - October 2000: visit to ITAMP and Dept. of Physics, Harvard Univ., Cambridge, U.S.A.
since 1. October 2000: professor (C3) for theoretical physics, University of Kaiserslautern,
2003 - 2009: member of editorial boards of Physical Review A and Journal of Modern Optics
May - September 2005: visit to ITAMP and Dept. of Physics, Harvard University
2006: call for W3 position at University Duisburg-Essen (F. Haake) - declined
since 2006: W2 professor for theoretical physics (special contract) at TU Kaiserslautern
2006 - 2010: speaker of DFG graduate college GRK 792
2008 - 2010: speaker of section “Quantum Optics and Photonics” of the DPG
2008 - 2012: member of the selection committee of the Alexander-von-Humboldt foundation for institutional partnerships
2010 - 2013: department head, Dept. of Physics, and member of Senate TU Kaiserslautern
2010 - 2016: member of editorial board (Divisional Associate Editor) of Physical Review Letters
2012 - 2018: member of the board (Vorstandsrat) of the German Physical Society (DPG)
since 2014: member of the Academy of Sciences and Literature, Mainz
2015 - 2020: member of the selection committee of the DFG senate for Collaborative Research Centers (SFBs)
since 2016: vice coordinator of DFG priority program GiRyd SPP 1929
since 2020: spokesperson of the Collaborative Research Center TR 185 “OSCAR”
2021 - 2023: spokesperson of the Steering Committee Research of Univ. of Kaiserslautern
2025: Herbert Walther award of the DPG and OPTICA (formerly Optical Society of America)