1. Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Str. 7, 07745 Jena, Germany
2. Institute for Quantum Optics and Quantum Information Vienna, Boltzmanngasse 3, 1090 Vienna, Austria
3. Friedrich Schiller University Jena, Abbe Center of Photonics, Albert-Einstein-Str. 6, 07745 Jena, Germany