Spin‐Decoupled Pancharatnam‐Berry Metasurfaces via Simultaneous Amplitude and Phase Control

ABSTRACT Pancharatnam‐Berry (PB) phase metasurfaces capable of continuous broadband phase modulation solely through rotation control of meta‐atoms have emerged as a pivotal branch in metasurface research. To achieve spin‐decoupled wavefront control in PB metasurfaces, current approaches introduce additional resonant phase, propagation phase, or exceptional topological phase; however, these strategies not only complicate the design but also inevitably lead to severe amplitude non‐uniformity across different meta‐atoms. Herein, we propose an alternative strategy by encoding the required dual‐phase information into an amplitude‐phase dataset. Utilizing double‐layer C‐shaped split‐ring resonators as meta‐atoms, two terahertz metasurfaces were designed and characterized for experimental validation. The first metasurface operates at 0.7 THz, reconstructing holographic “L” and “R” images under left‐ and right‐handed circularly polarized (LCP/RCP) illumination, respectively. The second metasurface generates holographic images of Arabic numerals 1–4 across four distinct channels (LCP and RCP incidence at 0.55 and 0.85 THz). This methodology significantly enhances polarization‐frequency multiplexing capacity, which may boost optical encryption, holography, and communications from the bottom up.