Orthogonal Flatbands-Enabled Robust Fano Resonances through Brillouin-Zone Folding
Abstract
Fano resonances based on coherent interference between localized Lorentz modes and Fabry-Perot radiation continua have been widely explored for microwave metamaterial sensors, filters, and photonic devices. However, conventional Fano metasurfaces suffer from angular dispersion and polarization-dependent spectral variations, limiting robustness under dynamic illumination. Here, we propose a band-folding-enabled flatband engineering strategy to realize robust Fano resonances in a planar microwave metasurface with a 2x2 enlarged cell of orthogonally arranged H-shaped metallic resonators. The enlarged cell induces Brillouin-zone folding, generating a nearly dispersionless flatband near 15.3 GHz with suppressed momentum dependence and enhanced photonic confinement. This flatband state provides a high-Q localized resonance strongly coupled to the FP radiation continuum, producing a stable asymmetric Fano response. Furthermore, the orthogonal resonator configuration supports two polarization-decoupled dipole modes with comparable excitation efficiency, reducing polarization-induced spectral distortion. Near-field measurements and simulations verify localized flatband features, while far-field experiments demonstrate stable Fano responses under oblique incidence from 0° to 30° with minor resonance variation. A temporal coupled-mode theory model is developed to quantitatively describe Fano spectral evolution under different illumination conditions. This work establishes a flatband-mediated route toward robust microwave Fano metasurfaces and offers a general strategy for stable resonant photonic device design.
Related
- Dilute-Limit Defect Displacements Enabled by Brillouin-Zone Sampling
- Chiral Unidirectional Resonances Enabled by Complete Coherent Radiation Control
- Enhanced Enantioselective Optical Trapping Enabled by Longitudinal Mie Resonances in Silicon Nanodisks
- Bound States in the Continuum and Unidirectional Guided Resonances Enabled by Competing Fourier Harmonics near the Fourth Stop Band
- The light carrying orbital angular momentum through time-varying scattering media using dual orthogonal-polarization channels
BibTeX
@misc{ye2026orthogonal,
title = {{Orthogonal Flatbands-Enabled Robust Fano Resonances through Brillouin-Zone Folding}},
author = {Yangsong Ye and Hanchuan Chen and Shijie Kang and Haitao Li and Ken Qin and Boyuan Ge and Xiexuan Zhang and Jingrong He and Jiusi Yu and Xiaoxiao Wu and Chunlei Yang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.25902},
eprint = {2609.25902},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.25902},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Orthogonal Flatbands-Enabled Robust Fano Resonances through Brillouin-Zone Folding
AU - Yangsong Ye
AU - Hanchuan Chen
AU - Shijie Kang
AU - Haitao Li
AU - Ken Qin
AU - Boyuan Ge
AU - Xiexuan Zhang
AU - Jingrong He
AU - Jiusi Yu
AU - Xiaoxiao Wu
AU - Chunlei Yang
PY - 2026
DA - 2026/09/22
PB - arXiv
DO - 10.48550/arxiv.2609.25902
UR - https://arxiv.org/abs/2609.25902
AB - Fano resonances based on coherent interference between localized Lorentz modes and Fabry-Perot radiation continua have been widely explored for microwave metamaterial sensors, filters, and photonic devices. However, conventional Fano metasurfaces suffer from angular dispersion and polarization-dependent spectral variations, limiting robustness under dynamic illumination. Here, we propose a band-folding-enabled flatband engineering strategy to realize robust Fano resonances in a planar microwave metasurface with a 2x2 enlarged cell of orthogonally arranged H-shaped metallic resonators. The enlarged cell induces Brillouin-zone folding, generating a nearly dispersionless flatband near 15.3 GHz with suppressed momentum dependence and enhanced photonic confinement. This flatband state provides a high-Q localized resonance strongly coupled to the FP radiation continuum, producing a stable asymmetric Fano response. Furthermore, the orthogonal resonator configuration supports two polarization-decoupled dipole modes with comparable excitation efficiency, reducing polarization-induced spectral distortion. Near-field measurements and simulations verify localized flatband features, while far-field experiments demonstrate stable Fano responses under oblique incidence from 0° to 30° with minor resonance variation. A temporal coupled-mode theory model is developed to quantitatively describe Fano spectral evolution under different illumination conditions. This work establishes a flatband-mediated route toward robust microwave Fano metasurfaces and offers a general strategy for stable resonant photonic device design.
ER -