By Linda Conlin, Pro to Pro Managing Editor

Combining holography and AI, researchers at Stanford have developed a prototype of glasses that can display full-color, 3D moving images over a direct view of the real world, but it looks like an ordinary pair of glasses. The researchers say that this prototype could transform fields from gaming and entertainment to training and education, where computed imagery might enhance or inform the wearer’s understanding of the world around them.

The prototype is the result of new approaches to complex engineering requirements that have so far produced either ungainly headsets or less-than-satisfying 3D visual experiences that can leave the wearer visually fatigued, or even a bit nauseous. This is due to current techniques for displaying augmented reality imagery that require the use of complex optical systems. In these systems, the user does not actually see the real world through the lenses of the headset. Instead, cameras mounted on the exterior of the headset capture the world in real time and combine that imagery with computed imagery. The resulting blended image is then projected to the user’s eye stereoscopically. The systems are bulky because they use magnifying lenses between the wearer’s eye and the projection screens that require a minimum distance between the eye, the lenses, and the screens.

The team moved beyond stereoscopic approaches in favor of holography, which is the production of holograms, three-dimensional pictures made by a complex pattern of light. Widespread adoption of holography has been limited by its inability to portray accurate 3D depth cues, leading to an underwhelming, sometimes nausea-inducing, visual experience. The researchers used AI to improve the depth cues in the holographic images. Then, using advances in nanophotonics and waveguide display technologies, the researchers were able to project computed holograms onto the lenses of the glasses without relying on bulky additional optics. Nanophotonics investigates the behavior of light on nanometer scales as well as interactions of nanometer-sized objects with light. Waveguide is a device that confines and directs the propagation of electromagnetic waves, such as visible light.

The team explains that by using this technology, when looking through the glasses’ lenses, the user sees both the real world and the full-color, 3D computed images displayed on top. The 3D effect is enhanced because it is created both stereoscopically, in the sense that each eye gets to see a slightly different image as they would in traditional 3D imaging, and holographically. The result of the new waveguide display techniques and the improvement in holographic imaging is a true-to-life 3D visual experience that is both visually satisfying to the user without the fatigue that has challenged earlier approaches. Unlike the bulky headsets of present-day augmented reality systems, the new approach delivers a 3D viewing experience in a compact, comfortable, and attractive form suitable for all-day wear.