IBM creates superfast computer interface

IBM boffins have created a device which could replace copper interconnects between chips with tiny silicon circuits that communicate at the speed of light.

The device, called a nanophotonic avalanche photodetector, is the fastest of its kind and may enable breakthroughs in energy-efficient computing that could have significant implications for the future of electronics.

The IBM device apparently uses the 'avalanche effect' of Germanium, a material currently used in production of microprocessor chips. A bit like an avalanche of snow, an incoming light pulse initially frees just a few charge carriers which in turn free others until the original signal is amplified many times.

Conventional avalanche photodetectors are not able to detect fast optical signals because the avalanche builds slowly. "This invention brings the vision of on-chip optical interconnections much closer to reality," said an IBM spokesboffin. "With optical communications embedded into the processor chips, the prospect of building power-efficient computer systems with performance at the Exaflop level might not be a very distant future.”

The avalanche photodetector demonstrated by IBM is the world’s fastest device of its kind. It can receive optical signals at 40Gigabits per second and simultaneously multiply them tenfold.

Perhaps the biggest breakthrough is that the device operates with just a 1.5V voltage supply, 20 times smaller than previous demonstrations. Which means that loads of these tiny communication devices could potentially be powered by a bog-standard AA battery.

"This dramatic improvement in performance is the result of manipulating the optical and electrical properties at the scale of just a few tens of atoms to achieve performance well beyond accepted boundaries," said Dr Assefa, the lead author on the paper. "These tiny devices are capable of detecting very weak pulses of light and amplifying them with unprecedented bandwidth and minimal addition of unwanted noise."

The IBM device is made of Silicon and Germanium, the materials already widely used in production of microprocessor chips and uses standard processes used in chip manufacturing.