Cascaded Ring-Resonators for Multi-Channel Optical Sensing With Reduced Temperature Sensitivity

Abstract

A configuration with cascaded ring-resonators is designed and demonstrated for realizing multi-channel optical sensing with reduced temperature sensitivity. The present configuration integrates a microring-based $1\times N$ wavelength-selective power splitter and $N$ microring transducers. The $1\times N$ wavelength-selective power splitter serves as a $1\times N$ power splitter and $N$ bandpass optical filters, which helps realize a compact chip with an optical sensor array. As an example, a sensor array with three microring transducers is demonstrated by using silicon-on-insulator nanowires. The present multi-channel optical sensor tolerates a temperature variation within $\sim 10^{\circ }\text{C}$ .