This tech breakthrough could be the turning point for smart glasses

Cambridge Consultants isn’t a company you have likely heard much about but it has been behind the scenes in many technological advancements since its founding in 1960. Many of the companies it works with it can’t discuss. We do know that it was the company behind the development of the first wrist-worn activity monitor, the Bluetooth chip that connects your phone to your car, and most recently, the new Smart Brick for Lego.

At this year’s CES in Las Vegas, the team showed me one of its latest breakthroughs in the work of smart glasses. One of the biggest challenges for manufacturers looking to integrate a screen into their smart glasses is to offer eye tracking while keeping the frames small and lightweight.

I spoke with Tom Watson, Head of Photonics at Cambridge Consultants, about a new system they have developed to help solve this problem. “I think what's really going to take them to the next level is mixed reality, but also powering that, doing eye-tracking, because then everything can know what you're looking at or what you want to interact with,” says Watson.

Conventional eye-tracking systems use a collection of infrared LEDs and cameras facing the eye to track the movement. Cambridge Consultants has created an alternative to this system that doesn’t require cameras. Instead, this uses a photonic light engine paired with either one or two photosensors.

“The problem with camera-based solutions is that cameras are actually quite large. There is a physical size, and you can't really compress them down any further before the quality deteriorates,” says Watson. “What we thought was, could we do it a different way, and only use one or two photosensor elements? But instead of using LEDs have a much more complicated light engine, putting the complexity into the illumination source.”

This system generates structured light patterns and sweeps across the eye up to 10,000 times per second to precisely track eye motion. The photonic integrated circuit routes light like an electronic chip routes electrons and is a world first for a chip of this size. These same photonic processes are being used at scale by Nvidia for its data centres to reduce cost and improve performance.

“In terms of being able to kind of generate structured light out of this kind of chip platform, in this kind of small element, this is a world first in what we're doing here,” says Watson. “It routes light around the chip the same way that an electronic chip routes electrons around.”

The system uses short-wave infrared light that is invisible to the wearer. This is safer than near-IR and more immune to sunlight, making it better suited to outdoor use, where smart glasses are likely to be used most.

It’s not just smart glasses where this technology could be used. The light engine could be paired with small camera sensors for higher accuracy 3D reconstruction of the eye or used in more complex VR headsets.

This is a technology that's only ever going to grow in this process,” says Watson. “Consumer miniaturised solutions, where there's millions of devices and they require advanced sensing solutions, are a perfect market to apply this.”

The success of smart glasses will ultimately come down to the ability to fit the technology into a wide range of lightweight frames – rather than the current bulky options. This new technology could make that possible, finally bringing in-lens display technology with eye tracking to the masses.