Open AccessNanofocusing of radially polarized light with dielectric-metal-dielectric probe
Author(s) -
Tomasz J. Antosiewicz,
Piotr Wróbel,
Tomasz Szoplik
Publication year - 2009
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.17.009191
Subject(s) - materials science , dielectric , optics , cladding (metalworking) , refractive index , optical fiber , optoelectronics , composite material , physics
Nanofocusing properties of a tip in the form of a dielectric tapered fiber with metal apertureless coating and dielectric nanocladding can be tuned within a wide spectral range by choice of cladding permittivity. The silica core of diameter decreasing from 2 mum to 5 nm in apex is covered with a silver layer and has a 5 nm dielectric cladding. Internal illumination with a radially polarized Laguerre-Gauss beam guided in fiber is used. In body-of-revolution finite-difference time-domain simulations we find that with an increase of the refractive index of nanocladdings the maximum enhancement occurs for increasingly longer wavelengths.