Hybrid-Waveguide Ring Resonator for Biochemical Sensing

This paper proposes a hybrid-waveguide ring resonator for on-chip biochemical sensing. Consisting of a low-loss strip-waveguide and a highly sensitive slot-waveguide integrated in a silicon photonic platform, it combines advantages of both waveguide types. In this way, it provides the unique feature to increase the sensitivity while maintaining low optical losses. Thus, this resonator structure may represent a promising alternative approach for future integrated biochemical sensing applications. This is suggested by a theoretical analysis, involving numerical simulation of the hybrid-waveguide ring resonator and an optimization of the slot-waveguide structure with regard to light-analyte-interaction. It is demonstrated that the hybrid-waveguide concept may overcome limitations in terms of overall resonator sensitivity, which is described by a figure of merit, connecting the optical losses with the resonator sensitivity.