1. Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
2. Institute of Applied Physics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
3. Insitute of Physics, Universität Rostock, Albert-Einstein-Strasse 23, 18051 Rostock, Germany
4. Otto Schott Institute of Materials Research, Friedrich-Schiller-Universität Jena, Fraunhoferstrasse 6, 07743 Jena, Germany
5. Fraunhofer Institute for Applied Optics and Precision Engineering, Albert-Einstein-Strasse 7, 07745 Jena, Germany