Open AccessDual‐Sensitivity Terahertz Metasensor Based on Lattice–Toroidal‐Coupled Resonance
Author(s) -
Lou Jing,
Yang Ruisheng,
Liang Jiangang,
Yu Ying,
Zhang Lei,
Zhang Chiben,
Li Tangjing,
Fan Yuancheng,
Zhang Fuli,
Wang Guangming,
Wang Jun,
Cai Tong
Publication year - 2021
Publication title -
advanced photonics research
Language(s) - English
Resource type - Journals
ISSN - 2699-9293
DOI - 10.1002/adpr.202000175
Subject(s) - terahertz radiation , resonance (particle physics) , resonator , physics , optics , toroid , metamaterial , rayleigh scattering , optoelectronics , atomic physics , quantum mechanics , plasma
High quality factor resonance with extremely narrow line‐width offers an important platform for terahertz (THz) sensing technology as it enables strong light‐matter interaction between THz waves and analyte materials. Lattice mode arising from the collective Rayleigh scattering of metamaterial periodic structures has the ability to strongly confine the electromagnetic waves on the surface that fails to radiate to the far‐field. Herein, for the first time, a strategy is experimentally demonstrated to design THz metasensors, which exhibit dual‐sensitivity of frequency and resonance intensity by coupling the first‐order lattice mode to the toroidal resonance. The frequency sensitivity mainly results from the localized field confinement, whereas the sensitivity of resonance intensity depends on the matching degree between toroidal resonance and lattice mode. It is found that both the frequency shift and resonance intensity show exponential growth with the increase in the analyte thickness. In addition, the sensing performance between toroidal and toroidal–lattice modes is compared to verify the superiority of the dual‐sensitivity property. This work would greatly improve the practical applications of THz sensing technology and open up new opportunities for the realization of slow light devices, multiband narrow filters, and nonlinear systems.