Multi-channel polarization-multiplexed camouflage coding metasurface based on Malus law

This paper proposed a multi-channel polarization-multiplexed metasurface based on the orientation degeneracy of Malus law, enabling near-field grayscale imaging, dual-spin far-field holography and camouflage encoding. By exploiting one-to-many mapping in Malus response, where the same optical intensity corresponds to multiple equivalent orientation angles, the amplitude constraint in cross-linearly polarized reflection channel was converted into geometric-phase selection freedom in cross-circularly polarized channel. This enabled collaborative design of near-field intensity modulation and far-field wavefront encoding. Under linearly polarized incidence, metasurface reconstructed a near-field grayscale image. Under circularly polarized incidence, propagation phase and geometric phase jointly formed spin-dependent phase responses, enabling independent holographic reconstruction in left circular polarization and right circular polarization channels. Furthermore, a programmable linear phase gradient was introduced to produce a preset spatial displacement between dual-spin holographic images, which were then superimposed to form a composite camouflage image. Meanwhile, near-field grayscale image served as a spatial mask during decoding, suppressing redundant structures and extracting target information. This method unifies amplitude, phase, and polarization degrees of freedom within a single metasurface, providing a scalable strategy for high-capacity polarization-multiplexed displays, optical information hiding and anti-counterfeiting encoding.