Chirality‐Assisted Spin‐Decoupled Metasurface Implemented by Simple Geometrical Rotation

Abstract Metasurfaces are distinguished by their ability to flexibly manipulate electromagnetic waves across multiple degrees of freedom. Designing metasurfaces with spin‐multiplexing often involve complex processes with multiple parameters to fine‐tune, posing significant challenges for achieving high accuracy. Here, a chirality‐assisted spin‐decoupled metasurface via solely simple geometrical rotation is theoretically proposed and experimentally demonstrated. In the meta‐atom design, a dual‐layered rectangular copper patch with a twist angle is used for enhancing circular dichroism through circular reflection patterns. A parallel cross structure is also introduced to independently control circularly polarized waves with specific handedness. Theoretical analysis and simulations demonstrate the robust decoupling capabilities of this meta‐atom design. Moreover, the theoretical deductions indicate that circular polarization decoupling can be achieved merely by rotating the meta‐atom structure, significantly reducing the complexity of designing circular polarization decoupling metasurfaces. To validate the practicality of the approach, a metasurface with lens and holographic imaging functionalities across two circular polarization channels is designed. Simulation and experimental results show excellent agreement with the theoretical predictions. This innovative method for circular polarization decoupling opens up promising new avenues for engineering applications in fields such as remote sensing, information encryption, and communication systems.