Open AccessResonance characteristics of independently tuned dual Fano of metal-dielectric-metal waveguide coupling square cavity with double baffles
Author(s) -
陈颖,
曹景刚,
谢进朝,
高新贝,
许扬眉,
李少华
Publication year - 2019
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.68.20181985
Subject(s) - fano resonance , figure of merit , resonance (particle physics) , optics , coupled mode theory , surface plasmon polariton , coupling (piping) , refractive index , materials science , square (algebra) , waveguide , baffle , surface plasmon , plasmon , surface plasmon resonance , optoelectronics , physics , atomic physics , nanotechnology , nanoparticle , geometry , mathematics , metallurgy , thermodynamics
A metal-dielectric-metal (MDM) waveguide coupling two square cavities with double baffles is designed in this paper based on the transmission characteristics of surface plasmon polaritons in subwavelength structure. The independent tuning of the dual Fano resonance is implemented by the interference between the wide-spectrum mode generated by the F-P (Fabry Perot) cavity and the two narrow-spectrum modes generated by the two square cavities. Moreover, the independent tuning of the dual Fano resonance can be achieved by changing the sizes of the two square cavities and filling medium. The coupled-mode theory (CMT) is adopted to analyze the transmission characteristics of the dual Fano resonance. The structure is simulated by the finite element method to quantitatively analyze the influence of structural parameters on the independent tuning of the dual Fano resonance and the refractive index sensing characteristics. The proposed sensor yields respectively sensitivity higher than 1020 nm/RIU and 1120 nm/RIU and a figure of merit of 3.29 × 10 5 and 1.17 × 10 6 by optimizing the geometry parameters. This structure provides an effective theoretical reference in the optical integration of ultra-fast optical switches, multi-function high-sensitivity sensors and slow-light devices.