Fig. 20
From: Waveguide-based augmented reality displays: perspectives and challenges
(a Is redrawn from [129], b, c are reprinted with permission from [130] © The Optical Society, and d is reprinted with permission from [131] © SPIE)
Schematics of achromatic display in a single diffractive waveguide. a Achromatic waveguide display using phase multiplexing VHGs. b Diffraction property and structure of nine-layer achromatic metagratings made of \(\text{TiO}_{2}\) and \(\text{SiO}_{2}\). c FDTD simulation result of such achromatic metagratings. d Structure of achromatic metagratings made of Al, Ag, and Au