The ability to focus light into a pattern rather than a point makes metalenses promising tools for carving circuits into silicon.
One of the more amazing new microdevices on the horizon is the metalens. This redesign of the traditional lozenge-shaped lens is a wafer-thin slab of silicon dioxide with a pattern of tiny trenches carved into the surface. The trenches are about the same size as the wavelength of light and influence the passage of photons through the slab, bringing them to a focus.
That turns these slabs into flat lenses. But the real benefit is that they can be carved onto ordinary silicon chips and thus made on the same fabrication lines.
That’s a big step. Until now, lenses have always been made separately and then assembled into optical components. Using metalenses would allow devices such as the cameras in smartphones to be made much more easily and cheaply. Metalenses might even allow entirely new designs of optical components such as optical chips.