Open AccessBroadband efficient directional coupling to short-range plasmons: towards hybrid fiber nanotips
Author(s) -
Alessandro Tuniz,
Markus A. Schmidt
Publication year - 2016
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.007507
Subject(s) - plasmon , planar , optics , broadband , materials science , nanowire , wavelength , surface plasmon , power dividers and directional couplers , waveguide , coupling (piping) , optoelectronics , coupled mode theory , photonic crystal fiber , optical fiber , refractive index , physics , computer science , computer graphics (images) , metallurgy
We present a broadband and efficient short-range plasmonic directional coupler design, for the delivery and collection of deeply sub-wavelength radiation to tapered plasmonic nanowires. We show a proof-of-concept design using a planar geometry operating at wavelengths between 1.2 -2.4 μm, showing that the propagation characteristics predicted by an Eigenmode analysis are in excellent agreement with finite element simulations. This analytical formulation is straightforward to implement and immediately provides the power-exchange properties of hybrid plasmonic waveguides. An investigation of both waveguide delivery and collection performance to and from a plasmonic nano-tip is performed. We show that this design strategy can be straightforwardly adapted to a realistic hybrid fiber geometry, containing wire diameters more than one order of magnitude larger than the planar geometries, with important applications in all-fiber plasmonic superfocussing, and nonlinear plasmonics.