Out-of-plane computer-generated multicolor waveguide holography

Multicolor waveguide holography remains a challenge due to its inherent design complexity, compounded by the limited low-loss materials available in the optical range as well as challenges in nanofabrication. In this study, we first propose and experimentally demonstrate a multicolor, computer-generated hologram (CGH) in an all-dielectric waveguide metasurface system. Light beams from three different color laser sources (red, green, and blue) are coupled into the waveguide via a single-period grating without any beam splitters or prisms. A multicolor holographic image can be decoupled in the far field through a binary metasurface CGH without any lenses. This technology enables lens-free, ultraminiature augmented and virtual reality displays.