High-Q titanium dioxide micro-ring resonators for integrated nonlinear photonics

We report on the nonlinear characterizations of the titanium dioxide micro-ring resonators (TiO₂ MRRs). By utilizing optimized fabrication processes, high quality factors (Q∼1.4 × 10⁵) doubling that of the previous work are achieved here for TiO₂ MRRs with high-confinement TiO₂ waveguides. The four-wave mixing (FWM) experiment results with low and high signal power demonstrate that, the fabricated TiO₂ MRRs can perform broadband (∼40 nm) wavelength conversion and cascaded FWMs. These achievements pave the way for key nonlinear photonic applications with TiO₂ waveguides and provide an efficient platform for various integrated photonic devices.