Advanced Photonics, Volume. 7, Issue 5, (2025)

Flatband high-Q metasurfaces inspired by coupled-resonator optical waveguides [Early Posting]

Sun Kaili, Cai Yangjian, Kivshar Yuri, Han Zhanghua
Author Affiliations
  • Shandong Normal University
  • China
  • Australian National University
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    We discuss a new class of high-Q nonlocal metasurfaces composed of weakly coupled optical waveguides with a periodically broken translational symmetry. The physics of such metasurfaces can be understood with the concept of coupled-resonator optical waveguides (CROWs) developed earlier for in-plane propagation in arrays of optical microresonators and photonic crystal cavities, allowing to realize photonic flatbands that exhibit uniform response to the resonant light across a wide range of incident angles. We suggest several realizations of this concept for anisotropic metasurfaces and demonstrate experimentally how such CROW-inspired metasurfaces can be employed to achieve unidirectional and bidirectional linear polarization flatbands, as well as chiral flatbands that are highly selective to the circular polarization of the incoming light.

    Paper Information

    Manuscript Accepted: Jul. 17, 2025

    Posted: Sep. 5, 2025

    DOI: AP