The digital cameras embedded in smartphones have made incredible progresses, killing point and shoot cameras and now getting close to kill reflex cameras. The quality of the photos has improved thanks to electronics (better digital sensors and faster processing chip) and to software (computational photography). What has seen very little improvement is the physical lens. Yes, the number of lenses has been growing, both the ones we see (as bumps on the phone surface) and as stacking (the new iPhone 12, as an example, stacks 7 lenses one on the other to improve quality) but the lens is still made of glass.
Now a new company, based in UK, promises to change the landscape: Metalenz has the goal of “transforming light via breakthrough flat-lens technology” (this is their eye catching slogan). For an in-dept view read this nice article on Wired.
Rather than using normal glass, Metalenz use meta-optics, structures made of silicon (glass is also made with silicon) and created with the same machinery/processes used in making silicon chips (the same silicon foundries are used). This of course has the added advantage of making mass production possible and affordable.
These meta-optic structures consist of clustering of nano lenses, each acting as waveguides. This is what a normal lens does too, the difference here is that in a normal lens the light beams are “bent” -refracted/diffracted- by the lens surface curvature, whilst here the light beams are “guided” as needed by each single substructure getting rid of refraction side effects (different wavelengths refract differently creating coloured fringes in your photo and you need to stack more lenses to correct these unwanted effects). There is no need of a curved surface, the lens is perfectly flat, nor for stacking more lenses hence the lens takes less space (no more bumps on your phone).
The benefits can be summarised as: smaller package, higher quality (up to 4x better in terms of controlled fringes and hence definition/sharpness) and lower cost in both production and assembly.
We should see meta-optics in our smartphones by the end of this year, 2022 models should embed this new optics, innovating for the first time in a while the optical part of the smartphone cameras.