Emission enhancement behaviors in the coupling between surface plasmon polariton on a one-dimensional metallic grating and a light emitter

The authors study numerically the enhancements of dipole radiation rate and emission efficiency in a structure of a sinusoidal interface between a half space of metal and a half space of dielectric. The surface plasmon polaritons (SPPs) generated at the interface couple with the dipole to enhance its radiation rate. The energy dependence of radiation rate relies on the factors of SPP density of state, dipole position, and the emission efficiency. Below the light line, the emission efficiency is controlled by the localized surface plasmon (SP) field distribution in coupling two counterpropagating SPP modes near the Brillouin zone boundary. A localized SP field distribution of higher intensity and higher emission efficiency leads to a higher dipole radiation rate and a higher emission fraction. (c) 2007 American Institute of Physics.