High Sensing Properties of Magnetic Plasmon Resonance by Strong Coupling in Three-Dimensional Metamaterials

Abstract

We present a method to enhance the sensing properties of a 3D metamaterial sensor. The concept is based on the combination of magnetic plasmon (MP) resonance in 3D metamaterials and a dielectric waveguide, in which a narrow-band hybrid MP resonance can be formed by the strong coupling of the MP resonance in the vertical split ring resonators (VSRRs) with a propagating optical waveguide mode in the dielectric waveguide. Because the hybrid MP resonance of the VSRRs are extremely sensitive to the changes in the refractive index of the material surrounding the VSRRs, the designed 3D metamaterial sensor has very high sensitivity (S = 300 nm/RIU, S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">*</sup> = 16/RIU) and figure of merit (FOM = 30, FOM <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">*</sup> = 390), which could find potential applications in label-free biosensing.