Structurally and materially sensitive hybrid surface plasmon modes in periodic silver-shell nanopearl and its dimer arrays

We numerically investigate the surface plasmon resonance (SPR) mode patterns in periodic silver-shell nanopearl arrays and its dimer arrays with the core relative permittivities filled inside the dielectric holes (DHs) by means of finite element method with three-dimensional calculations. Numerical results of resonant wavelengths corresponding to the effects of different period of unit cells, radii of DHs, illumination wavelengths, field propagation, electrical field stream lines, charge distributions, charge densities, half-body charge densities, and the DH core relative permittivities of periodic silver-shell nanopearls are also reported. It can be seen that the periodic silver-shell nanopearl arrays and its dimer arrays with DHs exhibit tunable SPR modes corresponding to the bonding and anti-bonding modes, respectively, that are not observed for the solid silver cases with the same volume. These results are crucial in designing localized SPR sensors and other optical devices based on periodic metal nanoparticle array structures.