Ag-SiO2-Ag based plasmonic waveguide for refractive index sensing

Abstract

In this paper, an Ag-SiO2-Ag based Metal-Insulator-Metal (MIM) plasmonic waveguide is investigated for Refractive Index sensing based applications. Dual resonators coupled to MIM waveguide is filled with material under sensing and the refractive index of the material is varied in the steps of 0.02 refractive index unit (RIU). The sensor is numerically analyzed using Finite difference in Time domain (FDTD) method. The interaction between resonators is observed and the sensitivity is measured. The sensitivity which is defined as change in resonance condition for per unit change in Refractive index unit (RIU) is obtained as high as 1145 nm/RIU. Proposed sensor finds its applicability in different refractive index based chemical and biological sensing.