The antenna, a century-old technology, is everywhere. Listening to the radio? Making a call on your cell phone? Surfing the web over Wi-Fi? The antenna made it all possible.
Now, the antenna is changing optics, too.
At Federico Capasso’s lab at Harvard University, researchers have devised a new way of manipulating light using nano-scale optical antennas. They effectively take a radio antenna, bend it into a V, and shrink it by a factor of about a million, to create what is called an “optical resonator.” By patterning a surface with a number of these resonators, bent at different angles—to create what’s known as a metasurface—they discovered they could get light to do just about anything they want.