Intel says light beams can replace electronic signals for future computers

The company said it has developed a research prototype employing extremely thin and light optical fibers and representing the world's first silicon-based optical data connection with integrated lasers.

Rick Nelson, Editor-in-Chief -- EDN, July 28, 2010

Intel has announced an advance in the quest to use light beams to replace the use of electrons to carry data in and around computers. The company said it has developed a research prototype employing extremely thin and light optical fibers and representing the world's first silicon-based optical data connection with integrated lasers. The link can move data over longer distances and many times faster than today's copper technology-up to 50 Gbps.

Justin Rattner, Intel chief technology officer and director of Intel Labs, demonstrated the Silicon Photonics Link at the Integrated Photonics Research conference in Monterey, CA. The 50-Gbps link is akin to a "concept vehicle" that allows Intel researchers to test new ideas and continue the company's quest to develop technologies that transmit data over optical fibers, using light beams from low-cost and easy-to-make silicon, instead of costly and hard-to-make devices using exotic materials like gallium arsenide. While telecommunications and other applications already use lasers to transmit information, current technologies are too expensive and bulky to be used for PC applications.

"This achievement of the world's first 50-Gbps silicon photonics link with integrated hybrid silicon lasers marks a significant achievement in our long term vision of ‘siliconizing' photonics and bringing high-bandwidth, low-cost optical communications in and around future PCs, servers, and consumer devices" Rattner said.

The 50-Gbps Silicon Photonics Link prototype is the result of a multi-year silicon photonics research agenda. It is composed of a silicon transmitter and a receiver chip, each integrating all the necessary building blocks from previous Intel technologies, including the first hybrid silicon laser co-developed with the University of California at Santa Barbara in 2006 as well as high-speed optical modulators and photodetectors announced in 2007.

The transmitter chip is composed of four such lasers, whose light beams each travel into an optical modulator that encodes data onto them at 12.5 Gbps. The four beams are then combined and output to a single optical fiber for a total data rate of 50 Gbps. At the other end of the link, the receiver chip separates the four optical beams and directs them into photo detectors, which convert data back into electrical signals. Both chips are assembled using low-cost manufacturing techniques familiar to the semiconductor industry. Intel researchers are already working to increase the data rate by scaling the modulator speed as well as increase the number of lasers per chip, providing a path to future terabit-per-second optical links.

This research is separate from Intel's Light Peak technology, though both are components of Intel's overall I/O strategy. Light Peak is an effort to bring a multi-protocol 10-Gbps optical connection to Intel client platforms for nearer-term applications. Silicon photonics research aims to use silicon integration to bring dramatic cost reductions, reach tera-scale data rates, and bring optical communications to an even broader set of high-volume applications.