Intraparticle surface plasmon coupling in quasi-one-dimensional nanostructures.

The optical properties of two-component quasi-one-dimensional nanostructures consisting of Au and Ni blocks have been investigated. The optically inactive component Ni plays a relaying role in the surface plasmon coupling both for the dipole mode and for the higher-order modes of gold blocks. The experimental results exhibit that the free electrons in Ni participate in the optical coupling phenomenon and that plasmon excitations in the Au blocks induce the free electrons in Ni to oscillate.