[29.02.2008 first posted on silicon republic]
IBM researchers have unveiled a prototype technology that could enable transmission of 8 terabits per second, equivalent to about 5,000 high-definition (HD) video streams, using the power of a 100-watt lightbulb.

The new technology uses light instead of wires to send information and has the potential to bring massive amounts of bandwidth to all kinds of machines in an energy-efficient way.
This kind of bandwidth can drive energy efficiencies inside data centres and speed up the sharing of large datasets, said IBM. Potential applications include scientists crunching data to discover new drugs and forecasting the weather, people sharing HD movies between devices and friends or doctors sending HD medical images to a specialist in seconds for diagnoses while patients are present.
The new optical technology could save massive amounts of power in supercomputers. For a typical 100metre long link, the power consumed by the optical technology is 100 times less than today’s electrical interconnects and offers a power saving of 10 times over current commercial optical modules.
This prototype ‘green optical link’ is designed to meet the bandwidth requirements for peta- and exa-flop supercomputing, marking a significant leap from related work unveiled by the same research team a year ago.
“Last year we unveiled an optical transceiver chip-set that could transmit a HD movie in under a second using highly customised optical components and processes,” said IBM Researcher, Clint Schow, part of the team that built the prototype.
“Just a year later, we’ve now connected those high-speed chips through printed circuit boards with dense integrated optical ‘wiring’. Now we have built an even faster transceiver and have moved the optical components away from custom devices to more standard parts procured from a volume manufacturer, taking an important step toward commercialising the technology.” The potential of this technology includes enabling widespread HD video sharing and video on-demand by dramatically increasing the bandwidth of video servers. Web-serving sites that host videos could use the technology to access libraries with millions of HD movies and video clips in seconds, speeding up access for users. By incorporating an optical data port in laptops, HD video recorders, personal MP3, video players, cell phones or PDAs, HD video content could be stored and displayed on high-resolution external screens. It also has potential applications in patient care, consumer electronics and supercomputing, where improved bandwidth will enable massively parallel supercomputers to have a profound impact in several fields, such as improving molecular dynamics calculations, accelerating drug discoveries, providing accurate weather/climate modelling, as well advancing our understanding of sub- nuclear physics such as quantum chromodynamics. The prototype revealed today is the world’s fastest and most integrated optical data bus that could lead an unprecedented number of high-performance computers connecting together to work as a single system.
The optically-enabled circuit boards, or ‘Optocards’, employ an array of low-loss polymer optical waveguides to conduct light between transmitters and receivers. The complete databus constructed with these Optocards incorporates a large number of high-speed channels and closely packs them to achieve unprecedented density: each waveguide channel is smaller in size than a human hair.
The packaging approach for the complete system is unique in that it utilises hybrid chip integration to produce a highly integrated optical module, or ‘Optochip’.
By Niall Byrne