Check out my news story at Optics & Photonics News: Growing Lasers on Silicon Or read more
Microprocessor performance is becoming limited not by the amount of calculations that chips can do, but by the speed with which data can be transmitted from one chip to another, or even from one part of a chip to another. This communications bottleneck would go away if we could transmit data as light, rather than as electrons. (If you doubt it would have that great effect: think about the huge change that occurred when long distance phone calls were converted to be carried via fiberoptics rather than copper wires. Suddenly more people could call the other side of the world, faster, and cheaper than they could before.)
But at a chip level, we need tiny light sources that can be built inexpensively onto the same chip as the electronic circuitry, controlled by the electronics, without using up too much room or requiring too much power.
We’re not there yet, and one of the problems is that making lasers from silicon is possible, but not easy or cheap. And growing lasers from something else on top of the silicon chips, or even growing them elsewhere and sticking them on like a gold star on a kid’s homework, is not yes mass-producible.
Still, this work from UC Berkeley showed that they could grow teeny tiny lasers — lasers that are smaller than the wavelength of the light they emit — on top of silicon, without doing the sorts of things that kill circuitry (like introducing metallic particles or heating it up to 700 degrees C), and the lasers emit pretty good quality light at room temperature.
It’s an excellent first step!
Check out my news story at Optics & Photonics News!