Efficient generation of surface plasmon by single-nanoslit illumination under highly oblique incidence

Bing Wang (1) , Lionel Aigouy (2) , E. Bourhis (3) , J. Gierak (3) , Jean-Paul Hugonin (1) , Philippe Lalanne (1)

1 Laboratoire Charles Fabry de l'Institut d'Optique / Naphel
2 Laboratoire Photons Et Matière
3 LPN - Laboratoire de photonique et de nanostructures

Using scanning near-field optical microscopy, we investigate the ability of nanoslits in metallic films to launch surface plasmon polaritons (SPPs) under highly oblique incidence at lambda=975 nm. The SPP generation efficiency is inferred by fitting the recorded near-field data with a simple analytical model. We find a remarkably large efficiency of 20% for the front side of the slit, which is in agreement with recent theoretical predictions relying on a fully vectoral electromagnetic formalism. An even larger efficiency is predicted experimentally (44%) and theoretically (33%) for the rear side. The present near-field analysis provides a direct approach to measure SPP generation efficiencies and may find applications for characterizing SPP devices.

Domains: Engineering Sciences [physics]; Optics / Photonic; Physics [physics]; Physics [physics]; Optics [physics.optics]

Bing Wang, Lionel Aigouy, E. Bourhis, J. Gierak, Jean-Paul Hugonin, et al.. Efficient generation of surface plasmon by single-nanoslit illumination under highly oblique incidence. Applied Physics Letters, 2009, 94 (1), pp.011114. ⟨10.1063/1.3068747⟩. ⟨hal-00570593⟩