Ring bound states in the continuum with broken time-reversal symmetry.

ABSTRACT: Bound states in the continuum (BICs) are general discrete mode points that typically have narrow-angle responses. To break this limitation on the performance of BICs, we propose a magneto-optical photonic crystal slab and study its eigen modes and far-field polarizations. Unlike general BICs, we find a continuous distribution with a ring shape for the quasi-BICs in k-space and analyze the forming mechanism. The ring BICs provide a special response of spatial directions and can be modulated by multiple structural parameters. Different from the linear polarizations of far-field from general BICs, the far-field polarizations within the ring qBICs are either ideally circular polarization or elliptical polarizations with all potential values of ellipticities leading to infinite density o

SUBMITTER: Fang YT 

PROVIDER: S-EPMC12719180 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature