Photonic integrated circuits based on cubic silicon carbide

Silicon carbide (SiC) gains momentum as a platform for realizing diverse applications in integrated photonics across both classical and quantum areas. This work focuses on photonic integration based on cubic SiC (3C-SiC), epitaxially grown on silicon, which provides properties such as a wide bandgap, high refractive index, and isotropic crystal structure. The usage of post-fabrication thermal annealing can significantly reduce waveguide loss in suspended 3C-SiC, enhancing SiC crystallinity and surface smoothness. On SiC-on-insulator (SiCOI) platforms, a flip, bond, etch, and polish method removes stacking faults and anti-phase boundaries at the SiC and silicon interface. Experimental studies demonstrate photothermal nonlinear responses, including optical bi-stability in both suspended 3C-SiC and SiCOI resonators. By using a CMOS-foundry-compatible fabrication process, we achieve a thin-film SiC Electro-Optic (EO) modulator operating at high optical power without signal degradation. Moreover, Kerr nonlinearity studies highlight the platform's thermal stability and polarization-independent responses. Future improvements include reducing chip-to-fiber coupling and waveguide loss.