Surface defect scattering of surface plasmon polaritons: Mirrors and lightemitters

We study the near-field and the angular distribution of radiation resulting from the scattering of surface plasmon polaritons from a surface defect by means of numerical calculations based on the use of the impedance boundary condition. Maximum reflection (plasmon mirrors) is found for half widths o n the order of the inverse of the surface plasmon wavevector, either protub erances or indentations, as predicted by a perturbation-theoretic argument. Maximum radiation (light emitters) occurs for wider protuberances, with co upling efficiencies beyond 80%. (C) 1998 American Institute of Physics. [S0 003-6951(98)04750-0].