The never-ending quest for thinner, lighter and more compact virtual reality (VR) and augmented reality (AR) devices primarily starts with display technology. From packing more pixels per inch (PPI) into displays to simplifying and streamlining the optics, it isn’t an easy process but Standford University researchers in conjunction with NVIDIA have recently showcased their latest project dubbed Holographic Glasses.
Most of a VR headset’s bulk comes from the distance between its magnifying eyepiece and the display panel, folding the light in as short a space as possible whilst maintaining quality and without distortion. Hence why most VR devices use Fresnel lenses as they off a good trade-off between optic weight and light refraction.
As part of SIGGRAPH 2022 which takes place this summer, NVIDIA and Stanford University have unveiled their latest research, glasses that create 3D holographic images from a display just 2.5 millimetres thick. Even thinner than pancake lenses, to make this possible the: “Holographic Glasses are composed of a pupil-replicating waveguide, a spatial light modulator (SLM), and a geometric phase lens” to create the holographic images.
The SLM is able to create holograms right in front of the user’s eyes thus removing the need for that gap more traditional VR optics require to produce a suitable image. While the pupil-replicating waveguide and the geometric phase lens help further reduce the setup depth. To produce an outcome that suitably combined display quality and display size the researchers employed an AI-powered algorithm to co-design the optics.
All of this inside a form factor that only weighs 60g.
As these are still early research prototypes this type of technology is still years away from deployment (or maybe never) with pancake lenses the next major step for most VR headsets. It has been rumoured that Meta’s upcoming Project Cambria will utilise pancake optics to give it a slimmer profile.
This isn’t the only VR collaboration between Stanford and NVIDIA for SIGGRAPH 2022, they’re also working on a paper looking at a “computer-generated holography framework that improves image quality while optimizing bandwidth usage.” For continued updates on the latest VR developments, keep reading gmw3.