Ultranarrow-linewidth wavelength-vortex metasurface holography

Metasurface holograms harness multiple degrees of freedom of light to enhance information channel capacity. Traditionally, wavelength multiplexing holography with high-capacity information channel was only achievable through 3D volume holograms using Bragg diffraction. Here, we demonstrate ultranarrow-linewidth wavelength-vortex multiplexing holography in metasurface holograms. By applying elementary dispersion engineering, we develop a sparse k -vector–filtering aperture array in momentum space, enabling sharp wavelength selectivity combined with orbital angular momentum selectivity. Further leveraging transformer neural networks for the design of phase-only holograms, we showcase the reconstruction of up to…