Color centers in solid state crystals have become a frequently used system for single-photon generation, advancing the development of integrated photonic devices for quantum optics and quantum communication applications. In particular, defects hosted by two-dimensional (2D) hexagonal boron nitride (hBN) are a promising candidate for next-generation single-photon sources, due to its chemical and thermal robustness and high brightness at room temperature. The 2D crystal lattice of hBN allows for a high extraction efficiency and easy integration into photonic circuits.
In this seminar, I will present our latest experiments in this field, where the fabrication parameters have been optimized such that quantum emitters of particular high quality are formed. An early application was a fiber-integrated device with fiber-coupled and free space collection capabilities. Furthermore, if coupled with nanophotonic structures such as micro-cavities, both, photophysical properties and collection efficiency can be enhanced. The single photon source is compact enough that it fits well within a 1U CubeSat. Such a space-compatible single photon source allows for fundamental tests of quantum mechanics in space and for satellite-based quantum communication.