Surface plasmon resonance in interacting Si nanoparticle chains

Interaction between the adjacent nanoparticles in a one-dimensional Si nanoparticle chain results in splitting of the surface plasmon resonance (SPR) into transverse and longitudinal polarizations, as well as spatial re-distribution of the SPR intensity, leading to local field enhancement in between the two nanoparticles. Such interaction is directly visualized using electron energy loss spectroscopy related techniques, which also disclose the longer impact parameter associated with the longitudinal mode SPR (as compared to that of the transverse mode SPR). By controlling the growth of Si nanostructures into different morphologies, we demonstrate that the material's optical properties can be manipulated.