Determination of loss coefficients of long-range surface plasmons

Abstract

Finite-width pump beams have been used to excite long-range surface-plasmon modes on thin silver films. These modes have been probed using both attenuated total reflection (ATR) and a new technique based on the spatial intensity profile of the reflected light. Our analysis of the spatial intensity profile of the reflected beam allows the separate determination of losses in the mode caused by reradiation and dissipation or scattering and agrees closely with the ATR method.