Researchers at Stanford University have taken the LED from your Christmas tree and shrunk it down to a tiny device that may one day help speed up computers and cool down power-hungry data centers.
They call it a nanoscale light-emitting diode. It’s an extremely tiny LED that packs a gallium arsenide resonator so that it can send and receive streams of data much like a laser. The nanoscale LED is much, much smaller than the laser interconnects used to send and receive information with fiber optic cable. It’s about 2,000 times as power efficient too.
Fiber optic is king when it comes to moving data over long distances, but if you want to shuffle bits around on a microprocessor — the tiny distance between two chip cores, for example — then copper still gets the job done.
But copper is hitting a wall. As chips start moving information around beyond 10 gigabits per second they’re getting too hot, and there’s too much interference in the copper wires. That’s why optical interconnects make sense. “You can’t really push the speed up and energy consumption is very big,” says Jelena Vuckovic, an associate professor of electrical engineering with Stanford University.
Most of the heat generated by microprocessors comes from these copper interconnects, says David Miller, another Stanford professor who studies optical interconnect technology. “It is power dissipation that today stops us from running electronic chips faster -– basically if we do that, they will melt”
Vuckovic’s team had to figure out a way to get LEDs to act like lasers. LEDs blast out light over an extremely broad emission spectrum and they’re not great at turning on and off really quickly. But the researchers can make the LEDs to go on and off super fast, and they’ve built a tiny resonator that focuses the LED emission into a single frequency.
Now all somebody has to do is figure out a way of bolting this on a microprocessor — a highly technical task that could take another 10 years of work.
Until then, good old-fashioned copper interconnects will probably have to do.