Surface plasmon resonance in metallic nanocylinder array

Localized surface plasmon resonances of noble-metal nanoparticles lead to high enhancements of local electromagnetic fields near the nanoparticle surface and play a key role in surface-enhanced Raman scattering, surface-enhanced fluorescence, near-field microscopy, and plasmonic devices. Recently, research results have shown that electromagnetic energy can transfer along a metallic nanoparticle chain because of coupled plasmon modes. In this paper, finite-difference time-domain method was used to study the surface plasmon resonances in coupled silver nanocylinder (nanoparticle) arrays and slab-like periodic modulation structures. From the far-field transmittance and reflectance, three different resonance modes were excited for the periodic nanocylinder arrays and only one resonance was excited for the periodic modulation structure. The near-field intensity distributions exhibited highly enhanced fields at the center of the gaps for nanoparticle arrays and at the caves of the periodic modulation structure.