ABSTRACT With the ever‐increasing demand for high‐capacity and chip‐integrated information storage, on‐chip metasurface‐enabled optical holography offers a promising solution by manipulating various optical parameters. However, the incident azimuthal angle, an essential optical degree of freedom (DoF), remains underexplored and limited due to the lack of arbitrary direction‐decoupled and effective phase‐encoding mechanisms, constraining both the multiplexing capacity and channel scalability. Here, we propose and experimentally demonstrate an omnidirectional‐incidence on‐chip metasurface for massive 3D meta‐holographic storage. Specifically, by leveraging angular‐independent detour phase modulation together with the conjugate relation of optical responses under opposite on‐chip illuminations, we break the conjugate constraint and extend the azimuthal multiplexing to 360° angular space, achieving full utilization of arbitrary angular DoF. As a proof of concept, up to 32‐channel multiplane 3D meta‐holograms are successfully reconstructed by sequentially switching the azimuthal angles to 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°, thereby surpassing typical azimuthal coding strategies. Moreover, our arbitrary azimuthal encoding for massive information storage relies solely on the displacements of identical meta‐atoms, simplifying design complexity and improving the fabrication robustness. We envision that the proposed omnidirectional azimuthal‐multiplexed on‐chip metasurfaces represent a powerful platform for high‐density optical information storage, high‐fidelity 3D displays, and secure optical encryption.
Cheng et al. (Thu,) studied this question.