The lens developed by Andrei Faraon’s team is only 1 micron thick (about one-hundredth the diameter of a human hair) and made out of silicon (http://bit.ly/1JVuWZG). This should make it possible to integrate these lenses in digital cameras and silicon electronics.
Conventional lenses work by bending light to focus it on a single spot. The thick center of the lens slows down light, so that the light entering the thinner edges can take a longer path from the edge to the center and everything will arrive at the focal point at the same time.
(Remember, light may have an absolute speed when traveling through a vacuum, but it slows down when it goes through air or glass.)
Faraon controls light bending and speed by creating arrays of stumpy nanoscale cylinders within the thin silicon film. Height and thickness determine the wavelengths with which the stumps interact. As light moves through the array, the stumps delay the passage of different wavelengths through different parts of the lens so everything meets at the focal point.
They researchers can focus up to 82 percent of the light passing through them. That’s much better than the few percent achieved by flat metal lenses, but not as good as the nearly 100 percent transmission achieved by high quality nonspherical lenses. On the other hand, the flat lenses are easier to integrate into semiconductor devices.
Unfortunately, they are not replacing your camera any time soon. Right now, they work only with narrow wavelengths, like red or infrared.
Still, Faraon thinks we could use them with lasers (which only emit one color), lithography systems used to make semiconductor devices, and display screens (which use only primary colors).
To learn more, see the full article at http://bit.ly/1JVuWZG.