Fluorescence from a single nitrogen-vacancy center in a diamond-based photonic crystal.
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Micro-Optics for Quantum Devices

Fluorescence from a single nitrogen-vacancy center in a diamond-based photonic crystal.
Image: L. Ghazaryan, IIAP (University Jena)
Photonic crystal in a diamond membrane (inset shows the e-field of the mode in the central cavity. Photonic crystal in a diamond membrane (inset shows the e-field of the mode in the central cavity. Picture: M. Steinert, IAP (University Jena)

Quantum physics enables a new generation of devices for various revolutionary applications.  Diamond and lithium niobate based micro- and nano optical elements are promising candidates for quantum devices. However, the durability of these materials against standard structuring techniques makes their processing very challenging.

In the past years, we have established a nanofabrication technology for nanostructuring of lithium niobate and Diamond using physical and reactive ion beam etching techniques. They are based on irradiation of the crystals with ions of various energies and subsequent selective removal of the damaged domains.  By controlling the irradiation and implantation parameters as well as the mask geometry, the 3D-shape of the optical element can be adjusted. 

Waveguide in a LiNbO3-on-Insulator (LNoI) layer. Waveguide in a LiNbO3-on-Insulator (LNoI) layer. Picture: IAP (University Jena)

Based on the gathered expertise, we currently work on nanostructuring and slicing of ultrathin membranes in single crystal Diamond.

Our focus lies particularly on the dedicated introduction of nitrogen-vacancy (NV-) color-centers in diamond-based photonic crystal membranes. These point defects in diamond serve as single photon sources with outstanding optical and spin properties. We explore various local activation methods and ways to enhance the photophysical properties of NV- centers.

Lilit Ghazaryan, Dr
Responsible Scientist