If you see a person who is carrying some kind of bulky equipment in front of him and waving his limbs from time to time, you can most likely guess that this person must be playing a virtual game. display device.

▲Image: NVIDIA
After many years of development, virtual reality technology has made great progress, but virtual reality headsets are still a bit bulky (too bad for cervical spine). Therefore, how to make them thin and light has become a problem that cannot be ignored in this field.
In an effort to make virtual reality headsets lightweight, NVIDIA and two research teams at Stanford University have published a paper highlighting latest research on virtual reality (VR) supercomputer Slim Holographic Glasses.

▲Image: NVIDIA
In fact, size of virtual reality headsets is still inconvenient to use. One of main reasons is technical barriers that have yet to be overcome. The display principle of today's VR head-mounted mainstream display devices is that left and right eye screens display images of left and right eyes respectively, and human eyes will generate a three-dimensional effect in mind after receiving this information. with differences.
In order for users to optically see images on screen in front of them, a lens is required to adjust the focal length. In addition, screens, sensors, cameras, processors, GPUs, and many other components need to be integrated in a single device, so it's hard to think about size.

▲Image: NVIDIA
In this case, shape of holographic glasses developed by Nvidia and Stanford research group is different from shape of other virtual reality display devices, which means that technology used is naturally different.
These ultra-thin holographic VR goggles consist of a pupil-like waveguide, a spatial light modulator, and a geometric phase lens. With a new algorithm that can perform correct phase calculations according to user's different pupil sizes, only 2.5mm thick components deliver a full color 3D holographic image through the optical stack.

▲Image: NVIDIA
It's worth mentioning that Reality Labs, Meta's VR R&D department, previously showed off a 9mm goggle-shaped VR display in development that creates holographic images using foldable optics and polarizers.

▲Image from: Meta
Compared to them, holographic glasses jointly developed by Nvidia and Stanford have more advantages, but unfortunately both products are under development and there are still many limitations that need to be improved.
For example, these holographic goggles are currently only shown as large-scale desktop models and wearable prototypes. The driver board is not included with goggles, which is still far from subtlety envisaged. The diagonal field of view is only 22.8°, and there are also 2.3mm static and 8mm dynamic eyecups, which means field of view is also quite limited and not up to practical level.

▲Image: NVIDIA
While Nvidia and Stanford's holographic VR glasses are technically imperfect, they will take time to resolve. But it also symbolizes hope: maybe in future we won't have to risk our neck to play in virtual reality.