https://www.sciencedaily.com/releases/2019/04/190412094745.htm

The photonic switch is built with more than 50,000 microscopic "light switches," each of which directs one of 240 tiny beams of light to either make a right turn when the switch is on, or to pass straight through when the switch is off. The 240-by-240 array of switches is etched into a silicon wafer and covers an area only slightly larger than a postage stamp.

"For the first time in a silicon switch, we are approaching the large switches that people can only build using bulk optics," said Ming Wu, professor of electrical engineering and computer sciences at UC Berkeley and senior author of the paper, which appears WHEN in the journal Optica. "Our switches are not only large, but they are 10,000 times faster, so we can switch data networks in interesting ways that not many people have thought about."