Controlling surface plasmon of several pair arrays of silver-shell nanocylinders

We studied, numerically, the characteristics of the surface plasmon of a system consisting of several pair arrays of silver-shell nanocylinders. Effects from different numbers of pair arrays, illumination wavelengths, and the core refractive index of silver-shell nanocylinders are studied by using the finite-element method. Results show that the peak wavelengths shift to shorter wavelengths (blueshifted) when the number of pair arrays increases from three to six. The near-field intensities in the gaps of the proposed type 1 structure can be tuned much stronger with a redshift by varying the wavelength of the incident light. The main features of surface plasmon effects can be qualitatively understood from some simple models of three, four, five, and six pairs of silver-shell nanocylinders.