Caltech’s tiny new chip can steer light in 74 quadrillionths of a second

A new Caltech device can redirect a beam of light in just 74 femtoseconds using another beam and a nanoscale silicon metasurface. The breakthrough could pave the way for dramatically faster photonic communications, computing, and sensing technologies. Caltech’s tiny new chip can steer light in 74 quadrillionths of a second.

A second beam can then pass through the material and get deflected according to the first beam’s projected pattern. To make those systems work, however, researchers need precise ways to control the direction of light and change it extremely quickly. Caltech researchers have now developed a device that uses one beam of light to redirect another in just 74 femtoseconds (74 quadrillionths of a second).

That is roughly the amount of time light needs to travel across the width of a human hair. "Steering light with light is very challenging because light typically interacts very weakly with matter. Using optical meta-surfaces (ultrathin carefully nanoengineered sheets), we can up the interaction strength to make this possible with much higher efficiency," says Harry Atwater, the Howard Hughes Professor of Applied Physics and Materials Science and the Otis Booth Leadership Chair of the Division of Engineering and Applied Science at Caltech.