Open AccessExperimental and theoretical investigation of waveguided plasmonic surface lattice resonances
Author(s) -
Håvard Ugulen,
Ranveig Flatabø,
Mansoor A. Sultan,
J. Hastings,
Martin Greve
Publication year - 2022
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.470017
Subject(s) - figure of merit , plasmon , fano resonance , materials science , surface plasmon resonance , refractive index , surface plasmon , optics , grating , dielectric , coupled mode theory , surface plasmon polariton , optoelectronics , lattice constant , lattice (music) , resonance (particle physics) , localized surface plasmon , nanoparticle , physics , nanotechnology , diffraction , particle physics , acoustics
Plasmonic nanostructures are good candidates for refractive index sensing applications through the surface plasmon resonance due to their strong dependence on the surrounding dielectric media. However, typically low quality-factor limits their application in sensing devices. To improve the quality-factor, we have experimentally and theoretically investigated two-dimensional gold nanoparticle gratings situated on top of a waveguide. The coupling between the localized surface plasmon and waveguide modes results in Fano-type resonances, with high quality-factors, very similar to plasmonic surface lattice resonances. By combining plasmonic surface lattice resonance and waveguide theory, we present a theoretical framework describing the structures. By immersing the fabricated samples in three different media we find a sensitivity of ∼50 nm/RIU and figure of merit of 8.9, and demonstrate good agreement with the theory presented. Further analysis show that the sensitivity is very dependent on the waveguide parameters, grating constant and the dielectric environment, and by tuning these parameters we obtain a theoretical sensitivity of 887 nm/RIU.