Dual quasi-bound states in the continuum in terahertz metasurfaces for high-Q resonance and multi-modal behavior
Abstract
Bound states in the continuum (BICs) suppress radiative leakage and enable high-Q resonances for terahertz (THz) photonics. Here, we propose a metallic quadrumer metasurface in which dual quasi-BICs are efficiently excited via translational-symmetry perturbations, while preserving the overall C4v symmetry, leading to polarization-insensitive operation. The two resonances originate from distinct BIC mechanisms, namely, a Γ-point symmetry-protected BIC and a Friedrich–Wintgen BIC arising from modal interference, and evolve into coexisting Fano and electromagnetically induced transparency (EIT)-like responses within the same design. Notably, the resonance frequencies remain nearly unchanged across the perturbation range, indicating strong spectral robustness due to negligible variation of the metasurface’s effective refractive index. Terahertz time-domain spectroscopy (THz-TDS) measurements show consistent overall trends with simulations, while discrepancies in Q-factor and spectral contrast are mainly attributed to metallic loss and fabrication/measurement non-idealities. This work provides a compact route toward polarization-robust, multi-mode high-Q THz metasurface devices for filtering, sensing, and dispersion control.
Article Details
Journal Info
Journal of Applied Physics
American Institute of Physics
Authors (8)
Yanyu Zou
Key Laboratory of Green Hydrogen and Advanced Catalysis of Jiangxi Province, School of Physics, Communication and Electronics, Jiangxi Normal University , Nanchang, 330022 Jiangxi,
Wangting Fu
Key Laboratory of Green Hydrogen and Advanced Catalysis of Jiangxi Province, School of Physics, Communication and Electronics, Jiangxi Normal University , Nanchang, 330022 Jiangxi,
Shuhan Wan
Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo China
Jianing Jiang
Key Laboratory of Green Hydrogen and Advanced Catalysis of Jiangxi Province, School of Physics, Communication and Electronics, Jiangxi Normal University , Nanchang, 330022 Jiangxi,
Shengbing Zhang
Key Laboratory of Green Hydrogen and Advanced Catalysis of Jiangxi Province, School of Physics, Communication and Electronics, Jiangxi Normal University , Nanchang, 330022 Jiangxi,
Can Tang
Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China
Hongyan Wang
Neuroscience & Behavioral Disorders Programme, Duke-National University of Singapore Medical School
Xingfang Luo
Jiangxi Provincial Key Laboratory of Green Hydrogen and Advanced Catalysis, College of Physics, Communication and Electronics, Jiangxi Normal University 1 , 99 Ziyang Avenue, Nanchang 330022, Jiangxi,