Ultra-high-speed optical communications link sets new power efficiency record

March 14, 2013

This shows optical link test chips, including transmitter circuits, laser diodes, photo diode, and receiver circuits (credit: IBM)

Ultrafast supercomputers that operate at speeds 100 times faster than current systems may now be one step closer to reality.

A team of IBM researchers working on a U.S. Defense Advanced Research Projects Agency (DARPA)-funded program have found a way to transmit massive amounts of data with unprecedented low-power consumption. They increased the speed by 66 percent while cutting the power in half, compared to the previous power efficiency record.

Specifically, they developed an optical communication link operating at 25 gigabits per second using just 24 milliwatts of total wall-plug power, or 1 pJ/bit (one picoJoule per bit). A Joule is measure of the amount of energy required to produce one watt of power for one second. A picoJoule is 10-12 Joule.

Scientists predict that the exascale supercomputers of the future will enable them to model the global climate, run molecular-level simulations of entire cells, design nanostructures, and more. Exascale refers to speeds in the range of 1018 computations per second (more precisely, 1018 floating point operations per second).

“We envision machines reaching the exascale mark around 2020, but a great deal of research must be done to make this possible,” says Jonathan E. Proesel, a research staff member at the IBM T. J. Watson Research Center in Yorktown Heights, N.Y.

To reach that mark, researchers must develop a way to quickly move massive amounts of data within the supercomputer while keeping power consumption in check.

The researchers combined innovative circuits in IBM’s 32-nanometer silicon-on-insulator complementary metal-oxide-semiconductor (SOI CMOS) technology with advanced vertical-cavity surface-emitting lasers (VCSELs) and photodetectors fabricated by Sumitomo Electric Device Innovations USA (formerly Emcore).

“We’re continuing the push for lower power and higher speed in optical communications. There will always be demand to move more data with less energy, and that’s what we’re working toward,” Proesel says.

The development will be presented at the Optical Fiber Communication Conference and Exposition/National Fiber Optic Engineers Conference (OFC/NFOEC) in Anaheim, Calif. March 17-21.