Compared to other semiconductor technologies, nanostructuring of diamond has so far been scarcely researched worldwide. In order to use diamond-based technologies in an application-relevant way, comprehensive know-how in process technology must be established and combined with expertise in quantum optics with solid-state nanosystems.
The Joint Lab Diamond Nanophotonics relies on existing work with defect centers in diamond and the unique manufacturing processes at Ferdinand-Braun-Institut. As a result, an unprecedented level of structuring quality, reproducibility and scalability shall be achieved. In particular, diamond nanostructures and photonic circuits will be interconnected using new methods. Such a platform can then be used as a toolbox for the photonic integration of established and new defect centers in diamond.
This advanced platform will enable various applications: extremely bright quantum light sources integrated into a compact package for commercial applications, as well as highly efficient spin-photon interfaces used to demonstrate entanglement operations.
Scanning electron micrograph of a diamond microstructure. The diamond-air interface has the shape of a parabolide (3D). The spin defect center (at the focal point of the parabolide) is coupled to single photons (red wave-like arrows) via optical transitions (red dashed lines). Photons are emitted into the far field, so that almost 50% of the emitted light is directed into the converging lens.
Scanning electron micrograph of a photonic diamond crystal nanocavity with integrated spin defect center. Spin levels (green arrows: "spin-up" & "spin-down") are connected to optical transitions (red dashed lines). They can be used as quantum memories and coupled to single photons (wavy arrow) to create spin-photon entanglements (dashed loop).
Noel H. Wan, Brendan J. Shields, Donggyu Kim, Sara Mouradian, Benjamin Lienhard, Michael Walsh, Hassaram Bakhru, Tim Schröder, Dirk Englund, “Efficient Extraction of Light from a Nitrogen-Vacancy Center in a Diamond Parabolic Reflector” Nano Lett. 18 (5) 2787-2793, (2018)