Open AccessUltra-compact high-sensitivity plasmonic sensor based on Fano resonance with symmetry breaking ring cavity
Author(s) -
GuiQian Lin,
Hui Yang,
Dongpeng Yan,
Dandan Wu,
Xuan Zhou,
Yunwen Wu,
Guangtao Cao,
Jian Chen,
Wanmei Sun,
Renlong Zhou
Publication year - 2019
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.27.033359
Subject(s) - fano resonance , coupled mode theory , resonator , plasmon , optics , asymmetry , symmetry breaking , physics , figure of merit , photonics , refractive index , optoelectronics , resonance (particle physics) , sensitivity (control systems) , quantum mechanics , electronic engineering , engineering
Miniaturizing optical devices with desired functionality is a key prerequisite for nanoscale photonic circuits. Based on Fano resonance, an on-chip high-sensitivity sensor, composed of two waveguides coupling with a symmetry breaking ring resonator, is theoretically and numerically investigated. The established theoretical model agrees well with the finite-difference time-domain simulations, which reveals the physics of Fano resonance. Differing with the coupled cavities, the Fano resonance originates from the interference between symmetry-mode and asymmetry-mode in a single symmetry-broken cavity. The spectral responses and sensing performances of the plasmonic structure rely on the degree of asymmetry of cavity. In particular, the plasmonic sensor can detect the refractive index changes as small as 10 -5 , and the figure of merit (FOM) of symmetry-breaking cavity structure is 17 times larger than that of symmetrical cavity system. Additionally, the sensitivity to temperature of ethanol analyte achieves 0.701 nm/ ○ C. Compared with the coupled cavities, the on-chip high-sensitivity sensor using a single cavity is more compact, which paves the way toward highly integrated photonic devices.