“…By nanostructuring SiC and improving the quality factor ( Q ) of the microring and microdisk resonators, NLO effects based on second-order and third-order nonlinear coefficients have been recently enhanced and observed (Figure a). Generally, the NLO response of 3C, 4H, and 6H-SiC nanostructures covering the optical spectrum from the visible through the mid-infrared and far-infrared, could open up a wide range of applications such as wavelength conversion, four-wave mixing (FWM) observed in both 4H and 3C-SiC, ,, second/third/fourth-harmonic generation observed in 4H-SiC microdisk resonators (Figure b–e), SHG, and difference frequency generation (DFG) in 3C-SiCOI microring resonators and waveguides, optical parametric oscillator (OPO) in 4H-SiC microring resonators, , parametric amplification in 4H-SiC crystal, frequency comb generation , (achieved with the lowest possible power generation efficiency after AlGaAs on-insulator; Figure f), self-phase modulation, and supercontinuum generation in 6H-SiC crystal from 1.3 to 2.4 μm. Nonlinear optical properties in 4H-SiC have been also investigated in the mid-infrared (mid-IR) where broadband emission from 3.90 to 5.60 μm was obtained from DFG.…”