Open AccessSensitivity enhancement of plasmonic grating in the local field
Author(s) -
Л. Л. Фрумин,
D. A. Shapiro
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.400382
Subject(s) - optics , materials science , grating , refractive index , local field , plasmon , electric field , total internal reflection , sensitivity (control systems) , rigorous coupled wave analysis , optoelectronics , nanowire , diffraction grating , physics , quantum mechanics , electronic engineering , engineering , condensed matter physics
A plasmonic grating consisting of parallel gold or silver nanowires on the glass substrate is an excellent sensor for refractive index measurement of a gas or liquid medium. We suggest measuring the local field in a gap between the wires to increase the sensitivity. The local electric field contains more information on the environment since it includes the evanescent waves. Calculation by the boundary element method confirms a substantial improvement of sensitivity owing to a sharp cusp-like gap resonance in the angular dependence. The local field measurement under the frustration of total internal reflection has promising prospects for the development of modern biomedical and chemical sensors.