1. Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany
2. Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
3. Department of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
4. School of Physics and Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
5. Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, Fraunhoferstr. 6, 07743 Jena, Germany
6. Abbe Center of Photonics and Faculty of Physics, Friedrich-Schiller-University Jena, Max-Wien-Platz 1, 07743 Jena, Germany