Dual Waveguide Coupled Microring Resonator Sensor Based on Intensity Detection

This paper systematically analyzes the device sensitivity of a dual waveguide coupled microring resonator sensor based on intensity detection. The relation between the device sensitivity and transmission coefficient, coupling coefficient, and operating wavelength has been derived and simulated, showing that the sensitivity can be enhanced by proper adjustment of the coupling coefficient and the operating wavelength. The explicit expressions of optimal self coupling coefficient t and operating wavelength are derived, serving as the basis for design and optimization. Simulations performed based on the experimental data lead to much smaller detection limit in terms of the effective index change deltan_eef. With a 30-dB signal-to-noise ratio measurement system, the optimized deltan_eef reaches ~10^-7 for both structures in this study, two orders of magnitude smaller than the previous results, f n conjunction with the analysis of the waveguide sensitivity, design guidelines are generalized and presented.

I. Introduction

Microring resonators have become a key building block for photonic integrated circuits due to their versatility in function and their capability of integration. They have been utilized in various applications including filtering [1], [2], switching [3], modulation [4], and wavelength conversion [5], mainly in the optical communications domain. Their compactness and compatibility with mature semiconductor fabrication platforms facilitates integration with microelectronic devices, leading to a great opportunity for mass-production and commercialization.