Spin-decoupled perovskite metasurfaces for multi-channel beam shaping and holographic imaging

This paper presents spin-decoupled perovskite metasurfaces for multi-channel beam shaping and holographic imaging, capable of simultaneously executing both functions within a single device. The work addresses the challenges associated with complex structures, limited functionality, and inadequate independent phase control for different polarized lights in existing coded metasurfaces. By leveraging the reversible switching between insulating and metallic states of perovskite materials, we achieve independent dynamic control over four polarization states: x-linear polarization (x-LP), y-linear polarization (y-LP), left circular polarization (LCP), and right circular polarization (RCP). In the insulating state of the perovskite, x-LP and y-LP are focused at distinct focal lengths; conversely, when switched to the metallic state, LCP and RCP transform into vortex beams characterized by different topological charges. The introduction of the spin decoupling principle that combines the propagation phase and the Pancharatnam-Berry (PB) phase makes wavefront processing possible and generates polarization-selective holograms in specific reflection channels. Regarding holographic display applications, the engineered metasurface can dynamically present various holograms based on differing polarization states and material conditions. This innovation offers novel perspectives for advancements in holographic display technology and encryption methods.