Multipolar origin and polarization-controlled high-<i>Q</i> quasi-BIC Fano resonances in dielectric metasurfaces for sensing applications.

ABSTRACT: We designed a multifunctional all-dielectric metasurface employing cuboid structures patterned with bow-tie-shaped nanoholes; it exhibits multiple Fano resonances induced by quasi-bound states in the continuum (quasi-BICs) through structural asymmetry. Among them, several resonant modes demonstrated high quality factors in the range of 10³-10⁴, along with near-unity modulation depth and strong spectral contrast. The optical responses were analyzed utilizing the finite-difference time-domain (FDTD) method, with Fano profiles fitted to theoretical models and the BIC-governed modes validated via the inverse-square ratio law. Furthermore, multipolar decomposition and electromagnetic spatial field profiles revealed the origins of the resonance, while LC circuit mode

SUBMITTER: Sarkar S 

PROVIDER: S-EPMC12834123 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature