Fig. 6
From: Waveguide-based augmented reality displays: perspectives and challenges
(a Is adapted from [73] with permission from AAAS. b Is adapted with permission from Feng et al. [74]. Copyright © 2022, American Chemical Society. c Is adapted from [75] with permission from AAAS. d Is adapted with permission from Sell et al. [76]. Copyright © 2017, American Chemical Society)
Different phase modulation mechanisms in metasurfaces. a Resonant phase modulation. b Propagation phase modulation. c Geometric phase modulation. d Nonlocal phase modulation