Tuning the plasmonic characters by fabricating a two-dimentional nanostructure from a straight nanochain

In this paper plasmon coupling between spherical gold nanoparticles equidistantly arranged in linear chain, V-shaped chain, and square arrays are investigated theoretically. Quasi-static analytical models are used to study near-field coupling of s-polarization and p-polarization in nanochain and nanoarray. The red and blue shifts of surface plasmon resonance (SPR) depend on the distance between the particles in the chain and on the polarization of the incident light. The calculated resonance wavelength pattern shows that the red and blue shifts are melted together when the arrangement of array turns isotropic. At the process of one liner chain turns into an array, both the red shifts and blue shifts become weaker. Furthermore, in the resonance wavelength pattern, the area of red shifts increases whereas the area of blue shifts finally vanishes. At the process of liner chain turns into V-shaped chain, the resonance wavelength pattern becomes un-centrosymmetric, and the maximum points of red shifts and the minimum points of blue shifts moves as the included angle between axes of V-shaped chain various. Through our study, controlling the resonance wavelength by regulating the arrangement of nanosized structure is achievable.