1. Physics Department, Paderborn University, Warburger Straße 100, 33098 Paderborn, Germany
2. Electrical Engineering Department, Paderborn University, Warburger Straße 100, 33098 Paderborn, Germany
3. Center for Optoelectronics and Photonics Paderborn (CeOPP), Paderborn University, Warburger Straße 100, 33098 Paderborn, Germany
4. Institute for Photonic Quantum Systems, Paderborn University, Warburger Straße 100, 33098 Paderborn, Germany