Steering Light in a Flash: New Chip Redirects Light Beams in Less Than a Trillionth of a Second

According to Caltech News, researchers have built a chip that steers a beam of light using nothing but another beam of light, redirecting it in as little as seventy-four femtoseconds—about the time it takes light to cross the width of a human hair. Conventional light-steering, like the panels in projectors, works by exciting a material's electrons and waiting for them to relax, which caps the speed at trillionths of a second. The Caltech team, led by Harry Atwater, sidestepped that delay using the optical Kerr effect, in which an intense 'pump' beam only nudges electrons within their orbitals, so the effect vanishes almost the instant the pulse ends. To make the faint effect strong enough to matter, they patterned a thin sheet of silicon with nanoscale pillars that trap and recirculate the light. The device deflected beams by up to thirteen degrees, and the researchers say the speed is currently limited only by the laser pulse driving it. The work appeared in Nature Nanotechnology and points toward faster optical computing and communications.

Listen to this story

Hear this and more stories in a personalized audio briefing.

Open The Chonkerton