Other
Diffractive Waveguide (in-coupling grating)
Category
Other
Abstraction level
Primitive
Operation level
Application
Use cases
AR/XR glasses opticsTransparent head-mounted displays (HMDs)Lightweight glasses with an AI assistant
How it works
An in-coupling diffraction grating injects light into a thin waveguide where it propagates by total internal reflection; an out-coupling grating directs the image to the eye, overlaying it on the real-world view.
Problem solved
How to deliver a microdisplay image to the eye in thin, light and transparent AR glasses?
Strengths & limitations
Strengths
✓Enables thin, lightweight AR glasses
✓Transparency (real world remains visible)
✓Compact integration with the microdisplay
Limitations
✗Brightness loss and rainbow artifacts (diffraction artifacts)
✗Limited field of view
✗Difficult, costly manufacturing of precise gratings