Open AccessTuning of nanofocused vector vortex beam of metallic granary-shaped nanotip with spin-dependent dielectric helical cone
Author(s) -
Fang Cheng,
Dengfeng Kuang,
Dong Liang,
Yanyan Cao,
Panchun Gu
Publication year - 2017
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.25.017393
Subject(s) - optics , electric field , optical vortex , vortex , dielectric , ligand cone angle , materials science , beam (structure) , physics , optoelectronics , quantum mechanics , thermodynamics , conical surface , composite material
We present the combined configuration of dielectric helical cone and metallic granary-shaped nanotip to produce three -dimensional vector vortex nanofocused optical field. The intensity and phase of the electric fields, and Povnting vector of the optical field generated by the combined configuration with linearly polarized illumination are studied with three-dimensional finite difference time-domain method. The localized vector electric field near the apex of the metallic granary-shaped nanotip is strongly depended on the chirality of the dielectric helical cone and the bottom radius of the metallic granary-shaped nanotip. The localized vector electric field is wavelength selective with the maximum intensity enhancement up to 10 4 times and minimum size of about 900 nm 2 , and the maximum radial electric field rotates 67.0° along z axis. This indicates the vector vortex beam generated by the combined configuration can be applied in nanofabrication, nano-sensing and nano-manipulation.