Low-scattering surface plasmon refraction with isotropic materials

We show theoretically and numerically that a planar structure consisting of two isotropic dielectric layers can be used to minimize parasitic scattering of surface plasmon polaritons for arbitrary incidence angle. The average scattering losses are reduced by an order-of-magnitude down to 1-3%. The surface plasmon refraction with the scattering suppression can be accurately described by an analytical model based on the Fresnel equations. The proposed approach can be used for the design of plasmonic lenses, reflectors, plasmonic crystals and plasmonic laser cavities. (C)2014 Optical Society of America