1. Friedrich Schiller University, Institute of Applied Physics, Abbe Center of Photonics , Albert-Einstein-Str. 15, 07745 Jena , Germany
2. Friedrich Schiller University, Institute of Physical Chemistry , Jena , Germany
3. Fraunhofer-Institute for Applied Optics and Precision Engineering IOF , Albert-Einstein-Str. 7, 07745 Jena , Germany
4. Friedrich Schiller University Jena, Institute of Solid State Physics , Max-Wien-Platz 1, 07743 Jena , Germany
5. Max Planck School of Photonics , Hans-Knöll-Straße 1, 07745 Jena , Germany