Analysis of triangular ring resonator using microcavity SOI slot waveguides

Abstract

We have proposed and analyzed high sensitivity and high Q-factor triangular ring resonator (TRR) with a total internal reflection (TIR) mirror in silicon-on-insulator (SOI) -based slot waveguide. Different from the conventional integrated optical devices such as waveguide, bend, splitter, and filter, in which the light is guided in high-index medium by the total internal reflection, the slot waveguide confines the E-field in the low-index region by way of strong discontinuities at the interface between the low-index core and the high-index claddings. Because the waveguide using these characteristic has a lower effective index than high-index waveguide, the TRR have been achieved high sensitivity, in which the long evanescent fields on a TIR mirror. Optical quality factor of up to 9.461x10² is calculated in such filters, and the sensitivity of the resonance shift for changing the refractive index of 1x10^-4 at the incidence angle of 34.11° has been identified as high as 1.02x10⁵ nm/RIU.