Engineers dream of replacing electricity inside computers with light. Silicon bends infrared light the way a prism bends visible light, so specific shapes of silicon could move infrared light along computer circuits the way optical fibers carry regular light.
The problem: There’s been no easy way to design the circuitry; the thousands of point-to-point connections have had to be designed one by one, making light-based computing impractical.
Now a Stanford engineering team has created a computer algorithm that designs backwards: The engineers tell the algorithm what they want the optical circuit to do and the circuit whips out the design, which can be programmed into machines that make microchips. The team’s early designs performed perfectly even with a few bugs yet to work out, indicating an easy scale-up to commercial production.