Allowing subwavelength-scale-digitization of optical wavefronts to achieve complete control of light at interfaces, metasurfaces are particularly suited for the realization of planar phase-holograms that promise new applications in high-capacity information technologies. Similarly, the use of orbital angular momentum of light as a new degree of freedom for information processing can further improve the bandwidth of optical communications. However, due to the lack of orbital angular momentum selectivity in the design of conventional holograms, their utilization as an information carrier for holography has never been implemented. Here we demonstrate metasurface orbital angular momentum holography by utilizing strong orbital angular momentum selectivity offered by meta-holograms consisting of GaN nanopillars with discrete spatial frequency distributions. The reported orbital angular momentum-multiplexing allows lensless reconstruction of a range of distinctive orbital angular momentum-dependent holographic images. The results pave the way to the realization of ultrahigh-capacity holographic devices harnessing the previously inaccessible orbital angular momentum multiplexing.

Material composition engineering and device fabrication of perovskite nanocrystals (PNCs) in solution can introduce organic contamination and entail several synthetic, processing, and stabilization steps. We report three-dimensional (3D) direct lithography of PNCs with tunable composition and bandgap in glass. The halide ion distribution was controlled at the nanoscale with ultrafast laser–induced liquid nanophase separation. The PNCs exhibit notable stability against ultraviolet irradiation, organic solution, and high temperatures (up to 250°C). Printed 3D structures in glass were used for optical storage, micro–light emitting diodes, and holographic displays. The proposed mechanisms of both PNC formation and composition tunability were verified.

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 118 independent images from a single hologram, achieving a simulated ultranarrow linewidth of 2 nanometers within the visible range. We apply these developed metasurface holograms for holographic visual cryptography, attaining unprecedented security levels with an information rate over 2500 times higher than traditional methods. Our results open exciting avenues for the application of metasurface holograms in various fields, including 3D displays, holographic encryption, and optical artificial intelligence.