Researchers have developed a new mathematical technique that quickly determines the ideal makeup and arrangement of millions of individual, microscopic features on a metasurface, to generate a flat lens that manipulates light in a specified way.
Previous work attacked the problem by limiting the possible patterns to combinations of predetermined shapes, such as circular holes with different radii, but this approach only explores a tiny fraction of the patterns that can potentially be made.
The new mathematical technique is the first to efficiently design completely arbitrary patterns for large-scale optical metasurfaces, measuring about 1 square centimeter — a relatively vast area, considering each individual feature is no more than 20 nanometers wide. The mathematical technique can quickly map out patterns for a range of desired optical effects.
The new technique can come up with the pattern that you should make for a lens that works well for several different colors, or you want to take light and instead of focusing it on a spot, make a beam, or some sort of hologram or optical trap.
Going forward, the researchers are working with engineers, who can fabricate the intricate patterns that their technique maps out, to produce large metasurfaces, potentially for more precise cellphone lenses and other optical applications.
These surfaces could be produced as sensors for cars that drive themselves, or in augmented reality, where you need good optics. The new technique allows you to tackle much more challenging optical designs.