Surface-plasmon-enhanced transmission through metallic gratings

Abstract

In a recent paper Ebbesen et al. [Nature 391, 667 (1998)] reported on extraordinary optical transmission through hole arrays in metallic films. They suggested an enhancement of the transmission by surface plasmons. Using the Chandezon method, we have performed numerical calculations for the transmission through silver gratings with very small slits. Our results agree qualitatively with Ebbesen's measurements. By evaluating the near field in the media above and below the metal we can verify that the astonishingly high transmission maxima indeed correspond to the excitation of surface plasmons on either side of the metal.