What is a waveguide display?

How it works

Augmented reality (AR) glasses need a light engine, the projector that creates the image, and a combiner that overlays it on the wearer's view. In a waveguide display the combiner is a thin piece of glass or plastic. A 2023 review in eLight explains that total internal reflection keeps light inside it, bouncing between its surfaces. An in-coupler sends the projector's light into the lens and an out-coupler releases it toward the eye. The review says this keeps headsets light and slim.

A 2021 review in Light: Science & Applications says some light exits at each bounce, copying the image across a wider area. The step is called exit pupil expansion.

Main types

The eLight review sorts waveguides into two groups:

• Geometric waveguides bring light in with a mirror or prism and send it out with an array of partial mirrors.
• Diffractive waveguides use gratings, microscopic repeating patterns that bend light. Surface-relief and volume holographic gratings were widely used in products such as HoloLens and Magic Leap, the review says.

Drawbacks it lists include rainbow effects, ghost images and eye glow, light leaking outward where bystanders can see it. The 2021 review said geometric designs usually give sharper, more evenly colored images but can be costly to make. It said diffractive waveguides then reached a field of view of about 50 degrees, with the ceiling set by the material's refractive index.

Where things stand in 2026

Microsoft lists HoloLens 2 optics as see-through holographic lenses (waveguides). Its release notes say HoloLens devices have not been made since December 2024. Meta says its Ray-Ban Display glasses use a geometric waveguide for a display in one lens, with 42 pixels per degree and 2 percent light leakage. They reached U.S. stores on September 30, 2025 at $799. Meta said on September 23, 2026 it was expanding sales to Canada, the UK, France, Italy and Germany. Meta says Orion, a prototype not sold to consumers, pairs high-refractive-index silicon carbide lenses with a field of view of about 70 degrees.

Some glasses avoid waveguides. IEEE Spectrum reported in November 2025 that Xreal's One Pro uses a flat prism instead. It said waveguides can produce artifacts such as colored halos. IDC said display glasses were 14.3 percent of XR headset and glasses shipments in the second quarter of 2026, up from 11 percent a year earlier.