Intel creates first end-to-end silicon-photonics connection with integrated lasers

Santa Clara, CA--Intel Corporation announced that it has developed a research prototype that is 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 gigabits per second (Gbps), says Intel.

Future data centers or supercomputers may see components spread throughout a building or even an entire campus communicating with each other by optical fiber, as opposed to being confined by heavy copper cables with limited capacity and reach. This will allow data-center users, such as a search-engine company, cloud-computing provider, or financial data center to increase performance and capabilities while saving significant costs in space and energy, or help scientists build more powerful supercomputers.

Concept vehicle

Justin Rattner, Intel chief technology officer and director of Intel Labs, demonstrated the silicon-photonics link at the Integrated Photonics Research conference (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 silicon rather than costly and hard to make devices using III-V semiconductors such as 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.

The 50 Gbps prototype is the result of a multiyear silicon-photonics research agenda, which included numerous "world firsts." It is composed of a silicon transmitter (with hybrid lasers in which indium phosphide is bonded to silicon; the silicon becomes part of the optical cavity) and a receiver chip, each integrating all the necessary building blocks from previous Intel breakthroughs 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 lasers, each with an optical modulator that encodes data 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 photodetectors. Both chips are assembled using low-cost manufacturing techniques familiar to those used in the semiconductor industry. Intel researchers are already working to increase the data rate by scaling the modulator speed as well as increasing the number of lasers per chip, providing a path to future terabit/s optical links.

Separate from Light Peak

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 terascale data rates, and bring optical communications to an broader set of high-volume applications.