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

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 x N wavelength-selective power splitter and N microring transducers. The 1 x N wavelength-selective power splitter serves as a 1 x 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 ~10 °C.