One glass, full color: Sub-millimeter waveguide shrinks augmented-reality glasses, uses scalable, large-area fabrication

https://phys.org/news/2025-05-glass-full-millimeter-waveguide-augmented.html

"not bulky/ heavy... lens itself guides virtual images directly to eye... separate waveguide layers for red, green, blue not required, overcome using achromatic metagrating handling all colors in single glass layer...  nanoscale silicon-nitride pillar array finely tuned by stochastic topology-optimization algorithm steering light with maximum efficiency... vivid full-color images using a 500-µm-thick single-layer waveguide... 9-mm eyebox... color, uniformity/ brightness outperforms... education, health care, gaming/ entertainment"