Fig. 4From: Waveguide-based augmented reality displays: perspectives and challenges(a–d Are redrawn from [52])Schematics of VHGs and PVGs. a structure of a PPVHGs. b structure of an HPDLC. b1 Schematics of local molecular rotation and distribution at zero voltage and b2 at field applied. c Interference of LCP and RCP light to produce a sinusoidal linearly polarized pattern. d Formation of PVGsBack to article page