Highly Sensitive Athermal Optical Microring Sensor Based on Intensity Detection

An athermal optical sensor using intensity detection based on silicon microring resonators (MRs) is presented. The thermally independent sensing is realized in the sensing zone within the temperature range ±5 K. The significant phase difference in the presence of an analyte between the low-Q coupled MRs is further sensitized through an interference-based intensity sensing scheme. Better performance of the coupled MR sensor compared to conventional microring sensors is demonstrated using transfer-matrix theory. For a measurement system of 30 dB signal-to-noise ratio, a detection limit of 6.8 ×10^-7 recognition indexing unit is predicted.