Optical bi-stability in cubic silicon carbide microring resonators

Citation:

Keith Powell, Jianfu Wang, Amirhassan Shams-Ansari, Bin-Kai Liao, Debin Meng, Neil Sinclair, Liwei Li, Jiangdong Deng, Marko Lončar, and Xiaoke Yi. 9/12/2022. “Optical bi-stability in cubic silicon carbide microring resonators.” Optics Express, 30, 19, Pp. 34149-34158. Publisher's Version
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Abstract:

We measure the photothermal nonlinear response in suspended cubic silicon carbide (3C-SiC) and 3C-SiC-on-insulator (SiCOI) microring resonators. Bi-stability and thermo-optic hysteresis is observed in both types of resonators, with the suspended resonators showing a stronger response. A photothermal nonlinear index of 4.02×10−15 m2/W is determined for the suspended resonators, while the SiCOI resonators demonstrate one order of magnitude lower photothermal nonlinear index of 4.32×10−16 m2/W. Cavity absorption and temperature analysis suggest that the differences in thermal bi-stability are due to variations in waveguide absorption, likely from crystal defect density differences throughout the epitaxially grown layers. Furthermore, coupled mode theory model shows that the strength of the optical bi-stability, in suspended and SiCOI resonators can be engineered for high power or nonlinear applications.