Two channel highly sensitive sensors based on 4×4 multimode interference coupler

A new microring resonators (MRR) based on 4×4 multimode interference (MMI) couplers for multichannel and highly sensitive chemical and biological sensors is proposed in this paper. The proposed sensor structure has advantages of compactness, high sensitivity compared with the reported sensing structures. By using the transfer matrix method (TMM) and numerical simulations, the designs of the sensor based on silicon nanowires are optimized and demonstrated in detail. The glucose and ethanol sensing by using our structure is investigated.