Optical tunneling effect and surface plasmon resonance from nanostructures in a metallic thin film

Surface plasmon resonance from metallic nanostructures significantly changes the optical response of the material. For metallic thin films with two-dimensional hole arrays or with one-dimensional periodic structures, extraordinary optical transmission has been demonstrated. We report progress on the surface plasmon resonance of periodic narrow-grooved metallic thin films. Two distinguishable modes, surface plasmon polaritons and localized surface plasmons, are associated with different periods. Simulation results demonstrate that the surface plasmon polaritons and localized surface plasmons are coupled with incident electromagnetic waves to resonantly tunnel through the periodic nanostructures. The broadness of localized surface plasmon resonance indicates that it could exist in randomly distributed, narrow-grooved structures as well.