Photonic-Cavity-Enhanced Laser Writing of Color Centers in Diamond.

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