High-sensing properties of magnetic plasmon resonances in double- and triple-rod structures

TL;DR

This study numerically demonstrates that magnetic plasmon resonances in double- and triple-rod structures exhibit high sensitivity to environmental refractive index changes, making them promising for advanced sensing applications.

Contribution

The paper introduces the use of double- and triple-rod structures to enhance magnetic plasmon resonance sensitivity for sensing, showing improved performance over single-rod electric plasmon modes.

Findings

Magnetic plasmon modes in DRS and TRS are highly sensitive to refractive index changes.

Magnetic plasmon modes exhibit a larger figure of merit than electric modes in SRS.

Hybridization effects lead to multiple magnetic plasmon modes with enhanced sensing capabilities.

Abstract

We numerically investigated the magnetic plasmon resonances in double-rod and triple-rod structures (DRSs and TRSs, respectively) for sensing applications. According to the equivalent circuit model, one magnetic plasmon mode was induced in the DRS. Due to the hybridization effect, two magnetic plasmon modes were obtained in the TRS. Compared with the electric plasmon resonance in a single-rod structure (SRS), the electromagnetic fields near the DRS and TRS were much more localized in the dielectric surrounding the structures at the resonance wavelengths. This caused the magnetic plasmon resonance wavelengths to become very sensitive to refractive index changes in the environment medium. As a result, a large figure of merit that is much larger than the electric plasmon modes of SRS could be obtained in the magnetic plasmon modes of DRS and TRS. These magnetic plasmon mode properties enable the use of DRSs and TRSs as sensing elements with remarkable performance.