Effective local-field confinement of silver nanoparticle dimer arrays

The optical properties of silver spherical nanoparticle dimer arrays with various incident wavelength are investigated by using the finite difference time domain method. Due to surface plasmon resonance, in the arrays of strongly coupled Ag nanoparticles, the energy of incident light is effectively confined in the gap of penultimate dimer under the influence of surface plasmonic reflection at the end of array structure. Furthermore, the suitable radius of the nanoparticles can be chosen to obtain the resonant peak at the optional position in the range of visible-nearinfrared wavelength. The above effects can be utilized to design effective functional end-structures in integrated optics.