Second-order Nonlinear Frequency Conversion and Integrated Color Centers in Silicon Carbide Nanophotonics

4H-Silicon carbide photonics offer the unique prospect of monolithic generation and frequency conversion of quantum light on-chip, as the material hosts color centers with favorable spin coherence properties and has a strong second-order optical nonlinearity. We integrate single color centers into thin-film nanophotonic devices and demonstrate efficient second-harmonic generation using a doubly resonant microring resonator scheme, which may be modified for quantum frequency conversion to the telecommunications band. We introduce color centers into thin films via electron irradiation and study the optical stability of single defects.