Facebook Reality Labs, the companys AR/VR R&D division, today published brand-new research demonstrating a method which integrates two key features: polarization-based optical folding and holographic lenses. In the work, scientists Andrew Maimone and Junren Wang state theyve used the method to create a practical VR display screen and lens that together are simply 9mm thick. The result is a proof-of-concept VR headset which could truly be called VR glasses.
Lets speak about how it all works.
The approach has other advantages beyond its extremely compact size; the scientists say it can likewise support significantly larger color range than todays VR display screens, which their screen makes development “toward scaling resolution to the limitation of human vision.”
Facebook released new research today which the company states reveals the “thinnest VR screen demonstrated to date,” in a proof-of-concept headset based upon folded holographic optics.
Why Are Todays Headsets So Big?
Unlike a picture, which is a recording of the light in a plane of area at an offered minute, a hologram is a recording of the light in a volume of area at a provided moment.
Now Im going to blow your mind. What if when you captured a hologram, the scene you caught had a lens in it? It turns out, the lens you see in the hologram will behave much like the lens in the scene. Do not think me? Watch this video at 0:19 at take a look at the magnifying glass in the scene and watch as it amplifies the rest of the hologram, despite the fact that it is part of the hologram itself.
Instead of using a series of common lenses (like the kind discovered in a set of glasses) in the folded optics, the scientists have actually formed the lenses into … holograms.
You can think about it like a paper with an arbitrary width. When you fold the paper in half, the paper itself is still just as broad as when you began, however its width inhabits less space due to the fact that you folded it over on itself.
Holographic Optics
This is the basic concept behind Facebooks holographic lens method. The scientists successfully caught a hologram of a genuine lens, condensing the optical homes of a genuine lens into a paper-thin holographic movie.
Lots of solutions have actually been proposed for making VR headsets smaller, and practically all of them consist of making use of unique screens and lenses.
But how the hell do you do that with light? Polarization is the secret.
So the optics Facebook is using in this design is, rather actually, a hologram of a lens.
Image courtesy Proof of Concept EngineeringIt turns out that beams of light have an orientation. Generally the orientation of beams at random, however you can use a polarizer to just let light of a specific orientation go through. You can consider a polarizer like the coin-slot on a vending machine: it will just accept coins in one orientation.
Every customer VR headset on the market uses effectively the same optical pipeline: a macro screen behind a simple lens. The lens is there to focus the light from the display into your eye. But in order for that to occur the lens requirement to be a few inches from the display screen, otherwise it doesnt have adequate focusing power to focus the light into your eye.
The brand-new research from Facebook proposes using both folded optics and holographic optics.
Photo by Road to VRIts natural to question why even the current VR headsets are basically simply as bulky as the very first generation of headsets that launched back in 2016. The response is basic: optics. Unfortunately the service is not so basic.
If that makes your head hurt, whatever is great. Holograms are nuts, but Ill do my best to explain.
However to go even thinner– to shrink the size of the lenses themselves– Facebook scientists have actually relied on holographic optics.
That essential range in between the lens and the screen is the reason every headset out there looks like a box on your face. The technique is still utilized today due to the fact that the lenses and the display screens are known amounts; theyre cheap & & simple, and although bulky, they accomplish a broad field of view and high resolution.
Folded Optics
When you look at a photo, you can only see the information of the light included in the airplane that was caught. When you look at a hologram, you can look around the hologram, due to the fact that the information of the light in the entire volume is recorded (also called a lightfield).
Using polarization, its possible to bounce light backward and forward several times along an optical path prior to eventually letting it out and into the users eye. This approach (likewise called pancake optics enables the lens and the display to move much better together, resulting in a more compact headset.
While the easy lenses in todays VR headsets need to be a particular range from the screen in order to focus the light into your eye, the concept of folded optics proposes folding that range over on itself, such that the light still traverses the very same range essential for focusing, but its course is folded into a more compact location.
What are folded optics? Its not rather what it seems like, once you comprehend it, you d be difficult pressed to come up with a better name.
Continue Reading on Page 2: Bringing it All Together
What if when you recorded a hologram, the scene you recorded had a lens in it? It turns out, the lens you see in the hologram will act just like the lens in the scene.
Every consumer VR headset on the market utilizes successfully the same optical pipeline: a macro display screen behind an easy lens. The lens is there to focus the light from the display screen into your eye. In order for that to occur the lens requirement to be a few inches from the screen, otherwise it doesnt have adequate focusing power to focus the light into your eye.
