Excitation of nonradiative surface-plasmon-polariton beams in nanoparticle arrays

Gaussian beams of surface-plasmon polaritons in suitably designed two-dimensional square-lattice arrays of noncontacting noble-metal nanoparticles can be produced upon near-field optical excitation. Both positive- and negative-refraction effects are possible in the same structure and can be accessed simply by switching the polarization.