At the IEEE’s International Electron Devices Meeting in Washington DC in December, IBM’s Dr Solomon Assefa announced a major advance in the ability to use light instead of electrical signals to transmit information for future computing. Using sub-100nm semiconductor technology for the first time, IBM has succeeded in integrating a nanophotonics circuit consisting of a photodetector and modulator side-by-side with silicon transistors, all fabricated on a single silicon chip.
The outcome of more than a decade of research, it will allow IBM ‘to move silicon nanophotonics technology into a real-world manufacturing environment that will have impact across a range of applications,’ according to Dr John Kelly, Senior vice president and director of IBM research. The company claims that it has solved the key challenges of transferring silicon nanophotonics into the commercial foundry.
This technology could provide relief to congested data traffic and an alternative to high-cost traditional interconnects. By adding processing modules into a high-performance 90nm CMOS fabrication line, a variety of silicon nanophotonics components such as wavelength division multiplexers (WDM), modulators, and detectors can be integrated side-by-side with a CMOS electrical circuitry. As a result, single-chip optical communications transceivers can be manufactured in a conventional semiconductor foundry, providing significant cost reduction over traditional approaches.
IBM’s silicon nanophotonics technology has already been shown to deliver data transfer of up to 25Gbps. It can feed a number of parallel optical data streams into a single fibre by utilizing compact on-chip wavelength-division multiplexing devices. It thus has the potential to deliver terabytes of data between computer systems and so silicon nanophotonics represents one solution to the rise of ‘big data’ challenges as the amount of data for analysis in research and industrial applications increases. The technology can be used in computer chips in servers, large datacenters, and supercomputers whether a few centimeters or few kilometers apart from each other, and move terabytes of data via pulses of light through optical fibers.