A Scalable Nanophotonic Platform for Rare Earth Ions*

Rare earth ion ensembles doped in single crystals are a promising platform with widespread applications in optical signal processing, lasing and quantum information processing. The ability to engineer nanoscale patterns surrounding these ions would enable strong light matters interaction and open possibilities for a new generation of photonic devices. We present a new nanophotonic platform with Thulium ions doped in single crystal Lithium niobate thin films on insulator, that supports scalable top down fabrication. The ions in the thin film retain bulk like optical properties. We show spectral hole burning in a nanophotonic waveguide with powers upto 2 orders of magnitude lower than previously reported bulk waveguides. Such a platform paves way for on chip lasers and efficient ensemble quantum memories. The high electro-optic coefficient of lithium niobate coupled with densly patterned electrodes promises large stark tuning which may be useful for ensemble quantum memory protocols like CRIB. Lastly strong light matter interaction can lead to Purcell enhancement and the ability to isolate single ions as a long lived qubit.