title: Enhanced nonlinear optical effects with a tapered plasmonic waveguide.
abstract: Infrared surface plasmon polaritons (SPPs) are concentrated in a laterally tapered planar Ag waveguide. The near field of SPPs excited with 1490 nm light at a Ag-sapphire interface is probed using the photoluminescence of upconverted Er ions at 550 and 660 nm. SPP interference patterns are observed that exhibit clear evidence of SPP concentration toward the taper end. The concentration leads to an enhancement of the upconversion luminescence intensity from Er energy levels that are populated by multiphoton processes.
authors.affiliation: Center for Nanophotonics, FOM Institute for Atomic and Molecular Physics (AMOLF), Kruislaan 407, 1098 SJ Amsterdam, The Netherlands. verhagen@amolf.nl
authors.forename: Ewold
authors.initials: E
authors.lastname: Verhagen
authors.forename: Laurens
authors.initials: L
authors.lastname: Kuipers
authors.forename: Albert
authors.initials: A
authors.lastname: Polman