title: Plasmonic nanofocusing in a dielectric wedge.
abstract: We show that surface plasmon polaritons (SPPs) can be concentrated to subwavelength dimensions in a nanoscale dielectric wedge on a metal substrate. An adiabatic model explains how SPPs propagating on a Ag substrate covered with a thin Si film of slowly increasing thickness become highly confined inside the Si layer. Simulations predict strong subwavelength focusing near the surface plasmon resonance frequency. Unlike alternative strategies, this method does not require the nanoscale shaping of metal surfaces.
authors: Center for Nanophotonics, FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG Amsterdam, The Netherlands. verhagen@amolf.nl
authors: Ewold
authors: E
authors: Verhagen
authors: L Kobus
authors: LK
authors: Kuipers
authors: Albert
authors: A
authors: Polman