High-Q adiabatic micro-resonators on a wafer-scale ion-sliced 4H-silicon carbide-on-insulator platform

A 4H-silicon carbide-on-insulator (4H-SiCOI) has emerged as a prominent material contender for integrated photon-ics owing to its outstanding material properties such as CMOS compatibility, high refractive index, and high second-and third-order nonlinearities. Although various micro-resonators have been realized on the 4H-SiCOI platform, enabling numerous applications including frequency conver-sion and electro-optical modulators, they may suffer from a challenge associated with spatial mode interactions, primar-ily due to the widespread use of multimode waveguides. We study the suppression of spatial mode interaction with Euler bends, and demonstrate micro-resonators with improved Q values above 1 x 105 on ion-sliced 4H-SiCOI platform with a SiC thickness nonuniformity less than 1%. The spatial-mode-interaction-free micro-resonators reported on the CMOS-compatible wafer-scale 4H-SiCOI platform would constitute an important ingredient for the envisaged large-scale integrated nonlinear photonic circuits. (c) 2023 Optica Publishing Group