There are two big limiting factors in scaling down a smartphone: The power source, and the camera. Perhaps for now, the answer to power supplies lies not in the nano area, but in the macro area: flexible cable-shaped batteries are just as good as anything else in storing electrical charge. But a new, flat lens is news that solves the other bulky issue.
"The antenna is nothing more than a resonator that stores light and then releases it after a short time delay."
Holes, acting as nanoantennae in the surface of a gold sheet, are responsible for this phase delay, focusing the light. The filtered wavelengths can be adjusted by changing the size, angle and spacing between the holes.
First flat lens focuses light without distortion –
Pattern of nanoantennas eliminates optical aberrations