Open AccessOptical antenna arrays in the visible range
Author(s) -
Daniel R. Matthews,
Huw D. Summers,
Kerenza Njoh,
Sally Claire Chappell,
Rachel J. Errington,
Paul J. Smith
Publication year - 2007
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.15.003478
Subject(s) - optics , surface plasmon , surface plasmon polariton , physics , plasmon , scattering , radiation , grating , antenna (radio) , collimated light , wavelength , laser , telecommunications , computer science
We report on experimental observations of highly collimated beams of radiation generated when a periodic sub-wavelength grating interacts with surface bound plasmon-polariton modes of a thin gold film. We find that the radiation process can be fully described in terms of interference of emission from a dipole antenna array and modeling the structure in this way enables the far-field radiation pattern to be predicted. The directionality, multiplicity and divergence of the beams can be completely described within this framework. Essential to the process are the surface plasmon excitations: these are the driving mechanism behind the beam formation, phase-coupling radiation from the periodic surface structure and thus imposing a spatial coherence. Detailed fitting of the experimental and modeled data indicates the presence of scattering events involving the interaction of two surface plasmon polariton modes.