Open AccessMagnetic modulation of far- and near-field IR properties in rod-slit complementary spintronic metasurfaces
Author(s) -
G. Armelles,
Luca Bergamini,
A. Cebollada,
María Ujué González,
Raquel Álvaro,
L. I. Van Torne,
Nerea Zabala,
Javier Aizpurua
Publication year - 2020
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.404046
Subject(s) - optics , materials science , magnetic field , electric field , modulation (music) , rod , surface plasmon , fano resonance , near and far field , plasmon , optoelectronics , physics , medicine , alternative medicine , pathology , quantum mechanics , acoustics
Complementary metasurfaces composed of randomly-placed arrays of aligned rods or slits are fabricated out of giant magnetoresistance Ni 81 Fe 19 /Au multilayers (MLs), a material whose optical properties change under the application of an external static magnetic field. The two metasurfaces are studied from both the experimental and theoretical viewpoints. The induced magnetic modulation (MM) of both the far-field signal and the resonant near field, at the rod/slit localized surface plasmon frequency, are found to obey the Babinet's principle. Furthermore, the near-field MM is found to be higher than the far-field counterpart. At resonance, both arrays show spots with high values of the magnetic modulated intensity of the electric near field (MM hot-spots). We show that this high magnetic modulation of the near-field intensity is very promising for the future development of high sensitivity molecular sensing platforms in the Mid- and Far-IR, using Magnetic-Modulation of Surface-Enhanced Infrared Absorption (MM-SEIRA) spectroscopy.