Caltech’s New Device Steers Light With Light at Mind-Bending Speed

A light-controlled meta-surface redirected another beam at femtosecond speeds without relying on slower electronic relaxation. A pulse of light crosses the width of a human hair in roughly 74 femtoseconds (74 quadrillionths of a second). Caltech researchers have now redirected a beam in that same fleeting interval by using a second beam as the control [...]