High-sensitivity optical sensors based on cascaded reflective MZIs and microring resonators

High-sensitivity optical sensors based on the cascaded reflective MZIs and the microring resonators are investigated theoretically and experimentally. The free spectral ranges of the microring and the reflective MZI are designed to be similar in order to produce Vernier effect. A high sensitivity of 1892dB/RIU of the optical sensor was achieved for the intensity interrogation. The measurement average power shows 13 dB increment comparing to that of the traditional two cascaded microring resonators. It's meaningful for the realization of the low-cost portable systems and application in biochemical sensing. (c) 2017 Optical Society of America