Plasmonic waveguides on silver nanorods and nanoplates

Noble metals like Ag, Au and Cu have complex permittivity in visible spectral range ε(ω) = ε(1)+ i ε(2) , where ε(1) < 0 and small ε(2) > 0. On metal/vacuum or metal/dielectric interfaces energy is transported due to localized surface plasmons, solutions of Maxwell equations. Subwavelength silver structures guide energy in confined modes, where amplitude of the optical field is considerably enhanced. This property should find application in construction of ultrafast nanoscale photonic devices. The smaller are metallic elements the stronger concentration of energy. This property have found application in near field microscopes. We analyze properties of periodic structures of silver nanorods arranged in hexagonal lattice and silver nanoplates ordered in herring-bone pattern. Using finite difference time domain method we illustrate energy transfer along the waveguide due to coupling between electromagnetic field and surface charges. One dimensional waveguide structures with desired properties may can be expanded to two and three dimensions. Attenuation in straight and curved waveguide segments is calculated for a wide range of wavelengths.