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