Nonlinear photonics in silicon carbide

Silicon carbide possesses unique optical nonlinearity, such as both high second-order and third-order nonlinearity. Wavelength conversion and generation based on these nonlinear processes have wide applications both in classic and quantum photonics. This chapter covers the nonlinearity of both 4H-SiC and amorphous SiC. The former presents the best performance for the time being and the latter has flexibility for material design with respect to refractive index and thickness. For 4H-SiCOI, four-wave mixing, optical frequency comb generation, and supercontinuum generation are studied. The derived nonlinear refractive index for TM mode doubles that for TE mode. For amorphous SiC, four-wave mixing are studied, and a nonlinear refractive index is derived for a-SiC with different refractive indices. The nonlinear refractive index increases with the refractive index, and it is one order of magnitude larger than that for 4H-SiC.