Thursday, March 11, 2010

"OPTICS: IBM Preps Optics to Replace Copper Interconnects"

Recently perfected optical interconnection technologies will accelerate multi-core microprocessors to 100-GHz--20-times faster than today--plus will lighten mobile devices to about half their current weight, by obsoleting the heavy copper wire used for routing electronic signals around on printed circuit boards (PCBs) and even between cores inside microchips. Look for all-optical electronic devices within five years. R.C.J.

Optical fibers already carry the fastest communications signals over the Internet and between servers and supercomputers at high-performance data centers. By encoding electronic communications in the language of light, the higher frequencies and wider bandwidth of optical signals not only increases performance, but obsoletes heavy, bulky copper-based interconnects in favor of small, lightweight optical fibers. Each year, IBM announces a few more elements in its nanophotonic toolkit, including on-chip silicon-laser resonators, modulators, waveguides and switches. Plus, it has demonstrated a complete chip-to-chip optical bus. Now IBM claims it has crafted the final tool in its nanophotonics kit -- a tiny germanium optical receiver called an avalanche photodetector -- that will enable it to realize the dream of integrated CMOS optical interconnects.

The new 40G bps photodetector can be integrated on the edge of processors to receive optical signals sent between chips instead of using copper traces on printed circuit boards. And eventually, it will be integrated on the top layer of the microprocessor itself to facilitate lightning-fast communications between cores on the same chip, thus eliminating the need for copper wires inside and outside future electronic devices. By eliminating the copper traces on printed circuit boards and the copper wires inside the chips themselves, a major reduction can be made in the weight of mobile devices today.
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