Intel has demonstrated the ability to combine indium phosphide, a material used in conventional lasers, with standard, low-cost silicon, in turn creating transceivers that can operate at 1 terabit-per-second speeds. That's about 1,000 times faster than the Ethernet connections currently used in data centers.
Conventional hardwired silicon transceivers provide the interconnection capabilities in most computer systems, but they're limited in range by the electrical properties of the metal wires used in the chips. The signals on the wires create electrical noise that limits distances between system components and computing platforms.
Optical devices, in contrast, don't generate noise. The telecommunications industry uses them to transmit data across distances of 25 miles and greater. Researchers have long understood the potential benefits of optical interconnections, but they can cost as much as $100,000 each, compared with the $1 per connection that Intel is targeting for its hybrid silicon laser.
If Intel can manage that, the optical technology could be used to connect boards to other boards and systems to systems, in addition to connecting components such as processors and memory in a PC or server.
Inside the data center, designers using the optical interconnection capability would no longer be limited to distances of between 17 and 20 inches between interconnections, as they are currently. They'd be able to spread out high-density loads into more isolated areas or create component "supercells," where large blocks of memory or microprocessors could be stored and shared across a company. High-heat loads also could be isolated and cooled directly.
"Imagine that distances no longer matter," says Victor Krutul, Intel's director of silicon photonics strategy.
Silicon lasers probably need another five years of development before they can be sold commercially, Krutul says. "We know how to build it," he says. "We've proven the science. We have all the individual components, and now we have to integrate them and make them fly."
Intel is undertaking its research in cooperation with the University of California, Santa Barbara, where John Bowers, a professor of electrical and computer engineering, is a known expert in indium phosphide research.