Open AccessCritical nanofocusing of magnetic dipole moment using a closed plasmonic tip
Author(s) -
Sun-Je Kim,
Seunghyuk Yoo,
Kyookeun Lee,
Joon-Soo Kim,
Yohan Lee,
Byoungho Lee
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.25.014077
Subject(s) - plasmon , multipole expansion , optics , magnetic dipole , magnetism , dipole , magnetic moment , magnetic field , nonlinear optics , materials science , reflection (computer programming) , surface plasmon , wavelength , nanophotonics , physics , condensed matter physics , laser , quantum mechanics , computer science , programming language
Squeezing magnetic dipole (MD) moment into a deep subwavelegnth apex of a tapered tip has not been achieved so far owing to a specific mode volume of a MD resonance which is dependent on an operating wavelength and back reflection of nanofocused waves. We propose a novel strategy for efficient delivery and nanofocusing of optical MD at an apex of a closed resonant plasmonic tip. Due to the ultracompact area (~λ 2 /900) of the nanocavity and resonances assisted by partial mirrors in a plasmonic waveguide, the enhancement factor of magnetic energy density is improved over 5 times. We expect that our scheme can help to investigate strong magnetic phenomena, including enhanced magnetic transition, artificial optical magnetism, multipole nonlinear optics, biomolecular sensing, magnetic near-field imaging, and spectroscopy.