Intel shows off ultra-fast silicon optical network

Intel has unveiled the prototype of a high-speed fibre optic data system based on silicon chips with integrated lasers and detectors. The system runs at 50Gbps, with Intel claiming future scalability to 1Tbps and beyond.

Unlike current systems, Intel's prototype does not depend on discrete components to generate and detect light; instead, these are part of the same silicon substrate that contains other components, and can be made at the same time on the same dies during chip fabrication.

"It's about bringing silicon manufacturing to optical communications, bringing Moore's Law to high-bandwidth communications for every computing platform, and revolutionising applications in the future", said Dr Mario Paniccia, Intel fellow and director of Intel's Photonics Technology lab.

 The demonstration system builds on many previous announcements by Intel, he said. "In 2004, nobody thought you could build a laser out of silicon. We've demonstrated them operating at 40Gbps; we've had modulators running at 40Gbps. Now the challenge is bringing them all together."

The demonstration system combines four different lasers operating at four discrete infrared wavelengths, with their light combined into a single output. At the receiver, the combined signals are split out into their individual wavelengths before being fed to four sets of very high speed photodetectors.

Because silicon is translucent at infrared wavelengths, portions of a chip can be used to create waveguides, mirrors, prisms and other optical components, with Intel's design of indium phosphide/silicon laser producing light that can be tuned by setting up different patterns of gratings on-chip. The company says that a single bonding process during production can create thousands of lasers, tuned to different frequencies, and that the quality of the light produced is very good.

Paniccia said that future developments were a matter of increasing the number of lasers per chip, and increasing the speed per laser. "We've shown most of our technology running at 40Gbps, and we can go to 25 lasers. That's a terabit a second," he said.

As optical fibre can go long distances compared to copper, he said, there were other advantages to integrated silicon photonics.

"How do we design computers differently if we don't have to cram things together? We can cool more efficiently, we can separate CPU and memory, increase performance, reduce system cost. As we move here, we'll revolutionise the way we design PCs and servers, how we design datacentres, and how we design cloud computing," said Paniccia.

For more on the technology, see the photo story Inside Intel's 50Gbps Silicon Optics