Visible-wavelength quantum photonics in a 4H silicon carbide platform

4H silicon carbide, as a silicon-based nonlinear optical material platform, exhibits a large bandgap energy, a wide transparent window and moderate second- and third-order optical nonlinearities. The availability of chip-based visible-wavelength nonlinear and quantum light sources pave the way for quantum communications as well as bio-, atomic-, and molecular-related nonlinear and quantum photonic devices and applications on a chip. Microring resonators on the 4H-SiC- on-insulator platform are ideal for efficiently generating nonlinear and quantum light sources integrated with large-scale photonic integrated circuits. In this work, we report our progress in demonstrating such quantum light sources in the visible/near-infrared wavelengths through spontaneous parametric down-conversion in 4H-SiCOI microring resonators utilizing the type-II phase matching.