Design and Optimization of an Optofluidic Ring Resonator Based on Liquid-Core Hybrid ARROWs

In this paper, we present the design and analysis of an integrated optofluidic ring resonator based on liquid-core hybrid polymer-silicon antiresonant reflecting optical waveguide (h-ARROW). We perform a modal analysis of h-ARROW using the finite-difference method, in order to find the optimized optical configuration, which accomplishes single-mode operation and reduced attenuation losses. An accurate investigation of the bend sections is performed to preserve the single-mode behavior with reduced propagation losses. A hybrid liquid-core multimode interference (MMI) device is used as a coupling element in the ring layout, and three possible MMI configurations are simulated and compared. By properly designing and optimizing each optical element, we demonstrate, by simulations, the possibility to achieve a quality factor up to 4 × 10⁴ with the extinction ratio of about 31 dB. Bulk and surface sensing performances of the device are also simulated and discussed.