Fig. 2
From: Waveguide-based augmented reality displays: perspectives and challenges
(a–c Are redrawn from [39]. d Is redrawn from [37])
Issues in geometric waveguide combiners. a Stray light generated by two reflections from the in-coupling mirror. b Stray light caused by undesired reflection from the back surface and c from the front surface of out-coupling mirrors. The blue arrows represent the desired light path, red arrows show the unwanted light path, and black circles indicate where the undesired reflection happens. d Stray light elimination on the in-coupler by replacing the mirror with an absorptive prism. The brown dashed lines represent the replaced mirror. Blue dashed arrows and blue arrows represent the beams from light engine when a mirror or an absorptive prism works as the in-coupler. e Eye glow generated by Fresnel reflections. The red dashed arrows represent eye glow towards environment, and blue arrows indicate the desired light path