Director of Display Systems Research at Meta✴ Douglas Lanman during Talk at the University of Arizona College of Optical Sciences showed images of the Mirror Lake virtual reality headset and stated that this was the case “Almost possible to build now”.
Meta✴ talked about the Mirror Lake concept last year. This is a VR headset that is characterized by its extremely compact dimensions – its dimensions are comparable to ski goggles. At the time, the company pointed out that it would require almost all of the advanced imaging technologies developed over the last seven years – Mark Zuckerberg suggested the Mirror Lake concept could be implemented in the second half of the decade, but Lanman believes that the project is already feasible, although you have to spend a lot of time on it.
All VR headsets on the market are equipped with fixed focus optics. Each eye has its own perspective, but the focal length remains the same, usually a few meters, although the eyes can be focused on different virtual objects. In 2018 meta✴then called up Facebook✴introduced a prototype half-dome headset that tracked eye position and mechanically moved displays to adjust focus, but it was not practical enough to bring such a product to market.
In 2019, the company announced the Half Dome 2 and Half Dome 3 projects. Half Dome 2 used more reliable propulsion and a more compact design; while Half Dome 3 took a completely different approach and did away with moving parts. Instead of moving the display, multiple layers of liquid crystal lenses were used. By applying voltage to the lens, you can change its focal length – 6 lenses give 64 possible focal lengths.
The Mirror Lake concept takes the same approach as Half Dome 3, but with an even more compact design achieved through holocake lenses. With these lenses, the light path is significantly shortened due to the polarization effect: the curved lens is replaced “thin, flat, holographic” — Holography does not mean the creation of a 3D image, but rather the effect of a holographic film.
Mirror Lake is still in development, but meta✴ Last year, a working prototype of a headset with Holocake lenses was already demonstrated – it was called Holocake 2. The most important feature of Holocake lenses is that only a laser can act as a light source for them – conventional LED backlighting is not suitable. And that’s a problem because laser sources don’t yet meet the power, size and price requirements required for consumer products.