Transparent Colored Display Enabled by Flat Glass Waveguide and Nanoimprinted Multilayer Gratings

In this paper, a type of transparent colored static display consisting of a flat glass waveguide and embedded multilayer gratings is presented, by which multiple patterns and colors with a wide field of view (FOV) can be displayed. The embedded grating is achieved by nanoimprinting followed by deposition of a high refractive index dielectric layer. The process can be repeated to produce multilayer gratings, which are shaped into specific patterns to be displayed, and they are designed to have proper periods and orientations to independently extract light incident from different edges of the glass plate. Such transparent display offers the advantages of low cost, easy fabrication and wide FOV, and it is suitable for colored signage and decorative applications.