Sensitivity enhancement of bimodal waveguide interferometric sensor based on regional mode engineering
In this paper, we propose a novel bimodal waveguide based on regional mode engineering (BiMW-RME). Leveraging the orthogonality of the guided modes, the form of patterned SiO2 cladding on the bimodal waveguide can reduce the interaction between the reference mode and the analyte, thereby significantly improving sensitivity. The proposed BiMW-RMEsensor experimentally demonstrates a phase sensitivity of 2766 π rad/RIU/cm and a detection limit of 2.44×1−5 RIU. The sensitivity is 2.7 times higher than that of the conventional BiMWsensoronthesameSOIplatform. The proposed design strategy demonstrates a significant improvement in the sensor’s sensitivity, presenting a novel approach to enhancing common-path interferometric sensor performance.
DOI: 10.1364/OE.519015
