1. Max Planck Institute of Quantum Optics, 85748 Garching, Germany
2. Department of Physics, Ludwig-Maximilians-Universität Munich, 85748 Garching, Germany
3. Institute for Physics, University of Rostock, 18051 Rostock, Germany
4. Department of Life, Light and Matter, University of Rostock, 18059 Rostock, Germany
5. J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, United States
6. Physical Chemistry, Freie Universität Berlin, 14195 Berlin, Germany
7. Department of Chemistry and Biotechnology, Darmstadt University of Applied Sciences, 64295 Darmstadt, Germany
8. Department of Physics, Umeå University, 90187 Umeå, Sweden
9. Center for Advanced Laser Applications, 85748 Garching, Germany
10. Department of Physics and CeNS, Ludwig-Maximilians-Universität, 80539 Munich, Germany
11. Physics Department, Georgia State University, Atlanta, Georgia 30303, United States
12. Max-Born-Institute, 12489 Berlin, Germany