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4H-silicon carbide (SiC) integrated platforms have shown great potential in quantum and nonlinear photonics. However, the thermal properties of 4H-SiC waveguides are still unknown, even though thermo-optic effects can play an important role in fundamental measurements and practical applications. In this paper, we comprehensively study the thermo-optic effects in a 4H-SiC microring resonator, by means of both temperature tuning and self heating. The thermo-optic coefficient and the ratio between the thermal absorption and the thermal diffusion of 4H-SiC are quantitatively measured to be 4.21 × 10−5 K−1 and 14.9 K W-1, respectively. Taking the acquired thermal properties into account, we experimentally achieve Kerr-nonlinearity based dual-pump optical parametric oscillation (OPO), and thus demonstrate that broadband solitons could feasibly be generated through thermal tuning of 4H-SiC-oninsulator (SiCOI) microring resonators.

Silicon carbide (SiC) has large refractive index, wide bandgap, and strong material-based second- and third-order nonlinearities. Thus, in recent years, SiC has attracted considerable interests in quantum and nonlinear integrated photonics [1] – [3] with potential applications within broadband nonlinear light sources, including photon-pair sources, supercontinuum generation, and frequency combs. Optical parametric oscillation (OPO) is regarded as a promising way to produce new frequencies and an important tool in generation of coherent light sources, such as frequency combs. In this work, we experimentally demonstrate a Kerr-nonlinearity based dual continuous-wave(CW) pumped OPO in a 4H-SiC-on-insulator (4H-SiCOI) microring resonator.

We report four-wave mixing with different polarization and spatial modes in a single 4H-silicon carbide photonic device. Our device shows great potential to perform high-dimensional multiplexing for optical communication and highdimensional entanglement in quantum networks. We use a polarization insensitive grating coupler and a multimode microring resonator that supports three polarization and spatial mode resonances. Finally, we show the polarization dependence of the third-order nonlinearity of 4H-silicon carbide. The measured nonlinear refractive index of the light polarized along the extraordinary axis, which is n2,TM=(13.1±0.7)×10−19m2/W, is twice as large as that of the light polarized along the ordinary plane, n2,TE=(7.0 ± 0.3)×10−19 m2/W, indicating that the extraordinary polarization is more efficient for nonlinear experiments in the 4H-silicon carbide integrated platforms as compared to the ordinary polarization.

4H-silicon carbide-on-insulator (4H-SiCOI) serves as a novel and high efficient integration platform for nonlinear optics and quantum photonics. The realization of wafer-scale fabrication of single-crystalline semi-insulating 4H-SiC film on Si (100) substrate using the ion-cutting and layer transferring technique was demonstrated in this work. The thermodynamics of 4H-SiC surface blistering is investigated via observing the blistering phenomenon with a series of implanted fluences and annealing temperatures. Surface tomography and the depth dependent film quality of the 4H-SiC have been extensively studied by employing scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Moreover, X-ray diffraction (XRD) was carried out and the diffraction spectrum reveals a narrow peak with a full width at half maximum (FWHM) of 75.6 arcsec, indicating a good maintenance of the single-crystalline phase for the prepared thin film of 4H SiC as compared to its bulk counterpart. With the single-crystalline 4H-SiCOI, we have successfully fabricated a micro-ring resonator with a quality factor as high as 6.6×104. The reported 4H-SiCOI wafer provides a feasible monolithic platform for integrated photonic applications.

Silicon carbide (SiC) exhibits promising material properties for nonlinear integrated optics. We report on a SiC-on-insulator platform based on crystalline 4H-SiC and demonstrate high-confinement SiC microring resonators with sub-micron waveguide cross-sectional dimensions. The Q factor of SiC microring resonators in such a sub-micron waveguide dimension is improved by a factor of six after surface roughness reduction by applying a wet oxidation process. We achieve a high Q factor (73,000) for such devices and show engineerable dispersion from normal to anomalous dispersion by controlling the waveguide cross-sectional dimension, which paves the way toward nonlinear applications in SiC microring resonators.

We realize silicon carbide-on-insulator platform based on crystalline 4H SiC and demonstrate high confinement SiC resonators with sub-micron waveguide cross-sectional dimension. The obtained Q (57,000) is the highest Q reported for SiC microring resonators.