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Ultra‐subwavelength focusing of light by a monolayer of metallic nanoshells with an adsorbed defect
Author(s) -
Yannopapas Vassilios,
Vitanov Nikolay V.
Publication year - 2008
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.200802180
Subject(s) - nanoshell , monolayer , diffraction , scattering , nanosphere lithography , materials science , optics , wavelength , plane wave , lithography , light scattering , optoelectronics , ray , plasmon , adsorption , plane (geometry) , nanophotonics , nanotechnology , physics , chemistry , medicine , alternative medicine , pathology , fabrication , organic chemistry , geometry , mathematics
We study theoretically the focusing properties of a two‐dimensional periodic array of silver‐coated silica nanospheres. The array contains an adsorbed nanosphere of the same type which serves as point source when the array is illuminated by a plane wave. By using a rigorous multiple‐scattering theory we show that under plane wave illumination, the array focuses the incident light in a tight area with size of about 1/70 of the wavelength. At the same time, the near‐field is amplified by three orders of magnitude. The frequency corresponding to the focusing and amplification effects depends on the thickness of the silver nanoshell offering a tunable response of the structure. The latter can find application in optical trapping, lithography and imaging below the diffraction limit. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)