4 ms·

> covered on one side with tiny structures Click bait. Not "completely flat" at all.

• lioeters 6y ago
  I believe the "flat" was meant in contrast to "curved", as in typical fisheye/ultra-wide-angle lenses. > the new fisheye lens consists of a single flat, millimeter-thin piece of glass covered on one side with tiny structures that precisely scatter incoming light to produce panoramic images. With a thinness of a millimeter, I'd say that's flat. The "tiny structures" are in the form of a film, which further qualifies as flat. > Their new metalens is a single transparent piece made from calcium fluoride with a thin film of lead telluride deposited on one side. The team then used lithographic techniques to carve a pattern of optical structures into the film. > Each structure, or “meta-atom,” as the team refers to them, is shaped into one of several nanoscale geometries, such as a rectangular or a bone-shaped configuration, that refracts light in a specific way.
• hombre_fatal 6y ago
  You should look at glass (something 99% of people would call "completely flat") under a microscope. The 3µm-wide structures in TFA deviate <1µm from the surface, so it's even flatter than glass, and your objection sounds rather petty.
  • noja 6y ago
    "The lens appears completely flat" would be a much better description, because the unflatness of the lens is the very thing that makes it work.