Machines

Waveguide For Display Panel Makes a Small Case for Better Timing

A chip-equipment giant losing China revenue is patenting glass coatings for AR glasses nobody can build fast enough yet.

Clay-diorama editorial illustration related to Waveguide For Display Panel.

What changes in this design

Normally, getting light to exit a flat waveguide panel toward a viewer's eye relies on a single patterned layer cut into the surface, without much attention paid to how the materials around it bend light. That can leave a display prone to sending stray light out the front, which anyone facing the wearer can notice as an unwanted glow.

Here, the layer above the panel, the patterned grating itself, and the coating placed over that grating are each given a defined range of light-bending strength, moving from moderate, to strong, to moderate again as light passes through. That step-by-step change is meant to help direct light toward the eye while reducing how much escapes outward.

Knowing this helps explain why a display might look clear from the wearer's side but still leak a faint glow that others can see nearby. It suggests that image quality and reduced glow can come from careful choices in ordinary materials and layering, not just from adding new mechanical parts to the device.

A glasses order nobody could fill

Meta ordered about 80,000 pairs of its Ray-Ban Display glasses from the waveguide maker Lumus, then raised that order 87.5 percent, to roughly 150,000, within six months. Even the higher number falls well short of the roughly 500,000 units Meta reportedly wants to move over two years. Rollout to the UK, France, Italy and Canada has been paused, with the company pointing to what it called extremely limited inventory. Reading through the numbers, I was surprised how little of the shortfall traces back to demand. People want the glasses. What nobody has enough of yet is a piece of curved glass that can steer light into your eye without also leaking it back out toward everyone standing near you.

That leak has a name: eye glow, the faint colored shimmer visible on the outside of a waveguide display when someone else is wearing one. It isn't dangerous. It's just the reason these devices still look, from three feet away, like they're quietly malfunctioning.

The glow a coating is supposed to fix

A patent published this month, filed by the semiconductor equipment maker Applied Materials in May 2024, goes after that glow directly. The application describes a waveguide display built in layers: an anti-reflective coating, a substrate with a refractive index between 1.5 and 2.7, a grating layer with an output coupler grating tuned to 2.1-2.5, and a further coating over the grating set between 1.5 and 1.9. Stacked correctly, the filing claims, this arrangement can pull eye glow down from the 40 to 60 percent the company says is typical of current commercial waveguides to somewhere between 0.05 and 10 percent.

That's a wide target range, and the filing doesn't say where in it a real product would land. My guess, and it is only a guess, is that the true figure sits much closer to 10 than to 0.05 - patents tend to claim the best case a lab has managed once, not what a factory can repeat at volume.

A fight already a decade old

None of this is new territory. One of the earliest headset makers in this space filed a very similar anti-reflective coating patent back in December 2018, describing four-layer and single-layer magnesium fluoride coatings tuned to the substrate's index, and claiming light transmission above 97 percent. A separate AR optics developer is chasing the identical eye-glow problem with different physics entirely: reflection gratings, dichroic notch filters tuned to red, green and blue light at 638, 520 and 455 nanometers, and dye or quantum-dot layers that simply absorb the stray light rather than bending it away. One of the largest software companies in the world filed its own answer, built around a two-dimensional metagrating rather than any coating at all, publishing its version on September 10, 2026, a week after the Applied Materials filing became public - though its version reportedly stops short of describing how anyone would manufacture that grating at scale.

Even the supply chain is consolidating around the problem. A Finnish maker of diffractive waveguides was acquired late last year by a much larger Asian electronics manufacturer, folding an optics specialist into a company that actually knows how to build things in bulk. Nobody I could find has published a per-unit price for a single Lumus waveguide, which says something about how tightly this supply chain is still held.

A side bet from a company under pressure

Applied Materials is best known for building the machines that make computer chips, not the chips or the glasses that use them. That core business is under real strain: China revenue fell to about $2.09 billion in its second fiscal quarter, down from $2.24 billion a year earlier, in a market that had supplied more than a third of the company's revenue not long before. The company has also guided to roughly $600 million in lost fiscal 2026 revenue from tightened U.S. export rules on chipmaking equipment. Against that backdrop, a patent on eyewear coatings looks almost like a hedge.

It isn't a new hedge, though. Applied Materials was already supplying what it called high-efficiency waveguides for a smart-glasses reference design built with a mobile chipmaker and a hardware design partner back in February 2024, three months before this specific filing was even submitted. I don't read this as a company chasing a trend; it looks more like one that placed a bet years ago and kept building on it quietly while its main business absorbs a much larger, more public hit.

The part worth watching

The optical fight is real, but it may not be the fight that decides this. An April 2026 analysis found that reflective waveguides, the kind Lumus makes, deliver optical efficiency almost an order of magnitude higher than the surface-relief grating designs Applied Materials works with, and without the color problems diffractive designs can have. Reflective waveguides are also far more expensive to manufacture, especially in glass - which is exactly the kind of high-precision, high-volume problem a semiconductor equipment company might, in theory, be well suited to solve.

Zoom out further and the whole category looks smaller than the excitement around it suggests. Shipments of smart glasses without any display at all surged 167 percent year over year in early 2026, on their way to roughly 13.6 million units for the full year; waveguide displays are a narrow slice of that, inside a segment expected to reach only about 27.3 million units by 2030. Our best information says the near-term winner in this category won't be decided by whose coating gets eye glow closest to zero. It will be decided by whoever can actually manufacture a waveguide, any waveguide, at a price and a volume that lets a glasses company stop rationing its own product. Applied Materials makes exactly the kind of machines that answer could depend on. Whether it plans to sell them for that purpose is not something a filing can tell you.

Sources

Reporting for this piece drew on the published filing and the references below.

The record, briefly. US20260259363A1, “Waveguide For Display Panel” Describes a waveguide display panel apparatus with an anti-reflective coating, a substrate (refractive index 1.5-2.7) above it, a grating layer with an output coupler grating (refractive index 2.1-2.5), and a coating over the grating (refractive index 1.5-1.9), aimed at improving output coupler performance and reducing eye glow.

More angles on this

When Flexible Light Guides Meet at the SeamAnother reading from the same G02B classification family, optical elements, systems or apparatus.
Optically Diffusive Film And Optical System Including Same Treats the Relationship as the PointAnother reading from the same G02B classification family, optical elements, systems or apparatus.
CPC G02B: Optical elements, systems or apparatusThe official classification family this record was filed into, published in the USPTO Cooperative Patent Classification scheme.
CPC F21V: Functional features or details of lighting devices or systems thereofThe official classification family this record was filed into, published in the USPTO Cooperative Patent Classification scheme.
Inside road safety system including multiple roadAnother reading from the wider G01W classification family, meteorology.

Read around this one:Public patent record USPTO published figure