Big Blue turns on light avalanche for faster chips - IBM

IBM said that it has created a device that allows electric signals to communicate using light pulses rather than copper wires.

The device is called a nanophotonic avalanche photodetector and IBM believes it will create breakthroughs in eneergy efficient computer.

The so called "avalanche effect" uses germanium - the effect is analogous to a snow avalanche, said the scientists. An incoming light pulse frees some charge carriers that then free others, amplofying the original signal. In other avalanche photodetectors the effect builds too slowly.

The avalanche multiplaction takes place in 10s of nanometers, with multiplication noise supressed by 50 to 70 percent compared to other gadgets.


Dr TC Chen, a VP at IBM Research, said that the development brings optical interconnections on semiconductors closer to reality. He said: "The prospect of building power efficient computer systems with performances at the Exaflop level might not be very distant."

The device can receive optical information signals at a billion bits per second (40Gbps) and multuiply them ten times, using a 1.5 voltage supply. Other avalanche detectors need 20 to 30 volt supplies, but IBM's gadget could be powered by an AA sized battery.

The report, Reinventing Germanium Avalanche Photodetector for Nanophotonic on-chip Optical Interconnects is published in Nature's March issue.

Intel has also been experimenting with similar devices.