Revealing Latent Exceptional Points of Linearly Anisotropic Metasurfaces via Asymmetric Polarization Basis Pairs

ABSTRACT Exceptional points (EPs), characterized by the coalescence of eigenvalues and eigenstates, exhibit a nontrivial exceptional topological (ET) phase that offers a distinct mechanism for wavefront engineering. However, current EP‐driven manipulations are mostly confined to circularly polarized (CP) eigenstates within non‐Hermitian systems, thereby severely limiting broader functional versatility. Here, by employing asymmetric input‐output polarization bases, a rigorous analytical mapping of the parameter‐space evolution is established, unveiling latent EPs and adjacent quasi‐EPs carrying opposite topological charges within linearly anisotropic systems. Arbitrary closed trajectories encompassing these twin singularities enable the independent control of two cross‐polarization channels across diverse polarization basis pairs distributed along mirror small circles on the Poincaré sphere. As a proof of concept, a single metasurface experimentally substantiates the proposed theoretical framework by executing holographic validations under distinct polarization pairs. Our findings provide a feasible approach for deterministically tailoring dual channels across a versatile spectrum of polarization pairs, thereby extending the applicability of topological singularities within linearly anisotropic systems for wavefront multiplexing and polarization encryption.