Speckle-free single-layer metasurface holograms

We introduce high-resolution speckle-free holograms, created using polarization manipulating metasurfaces. The holograms enable clear projection of 2D and 3D images, in contrast to conventional holograms with significant speckle noise. The approach uses a simple non-iterative algorithm at a low computational cost. As a proof of concept, we demonstrate a reflective hologram composed of silicon nitride nanoposts on an aluminum layer that projects a high-resolution grayscale image. By implementing three holograms for primary colors, full-color far-field and 3D holograms become feasible, with potential applications in anticounterfeiting tags.