Plasmonic-dielectric hybrid interferometric structures for high-sensitivity refractive index sensing

Abstract

In this work, we present a parametric study, by means of numerical simulations, of an integrated Mach-Zehnder interferometer, where the sensing arm consists of a long-range surface plasmon polariton waveguide. Our hybrid dielectric-plasmonic structure is designed specifically for biologically relevant situations, where high-sensitivity sensing of refractive index is critical for tracing small changes in analytes which are commonly presented in aqueous solution form. The design of our device is realistic as it can be fabricated with commercial-grade materials that are commonly available in clean room facilities. Overall, our results validate the use of the proposed structure for high-sensitivity refractive index sensing, based on the sensitivity obtained in our study.