Photonic-Cavity-Enhanced Laser Writing of Color Centers\nin Diamond

Color centers in\ndiamond have widespread utility in quantum technologies,\nbut their creation process remains stochastic in nature. Deterministic\ncreation of color centers in device-ready diamond platforms can improve\nthe yield, scalability, and integration. Recent work using pulsed\nlaser excitation has shown impressive progress in deterministically\ncreating defects in bulk diamond. Here, we extend this laser-writing\nprocess into nanophotonic devices etched into diamond membranes, including\nnanopillars and photonic resonators with writing and subsequent readout\noccurring in situ at cryogenic temperatures. We demonstrate the optically\ndriven creation of carbon vacancy (GR1) and nitrogen vacancy (NV)\ncenters in diamond nanopillars and observe enhanced photoluminescence\ncollection from them. We also fabricate bullseye resonators and leverage\ntheir cavity modes to locally amplify the laser-writing field, yielding\ndefect creation with picojoule write-pulse energies 100 times lower\nthan those typically used in bulk diamond demonstrations.