Date: 10/12/2012

IBM gets further closer to photronics chip; combination of photonics and electronics

For a high speed communication engineer, copper is like ordinary car to F1 racer. Terabit (Tb) speed loving High speed designer employs photons otherwise light to send Tera bytes of data both for long distance and short distance. Today's chip designers are forced to use metal conductors in pure silicon based semiconductor ICs due to limitations in Silicon's properties to convert electrical signal into light and vice versa. With a requirement of multiple processors simultaneously processing video and any such complex data with seamless movement of data and processing instruction across different processors there is a requirement of high speed intra-connect on-chip and high speed inter-connect off-chip in a complex computing system. Copper interconnect is irritatingly complex and slow. This forces semiconductor designers to either make silicon to emitt and recept light or use any other material which can easily integrated with present chip manufacturing process.

The tech-master IBM is continuously working on this for long time and now has announced break through in on-chip photonics, where both electrical and optical interconnects run one next to the other, kind of photronics! IBM has called this breakthrough technology as “silicon nanophotonics” – allows the integration of different optical components side-by-side with electrical circuits on a single silicon chip using, for the first time, sub-100nm semiconductor technology.

IBM says Silicon nanophotonics takes advantage of pulses of light for communication and provides a super highway for large volumes of data to move at rapid speeds between computer chips in servers, large datacenters, and supercomputers, thus alleviating the limitations of congested data traffic and high-cost traditional interconnects.

According to Dr. John E. Kelly, Senior Vice President and Director of IBM Research, this allows them to move silicon nanophotonics technology into a real-world manufacturing environment that will have impact across a range of applications.

Silicon nanophotonics technology supports processing of Big Data by seamlessly connecting various parts of large systems, whether few centimeters or few kilometers apart from each other, and move terabytes of data via pulses of light through optical fibers.

IBM has done this by adding a few 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 are 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, as per IBM.

Nanophotonics transceivers can handle data rate of 25Gbps per channel. In addition, the technology is capable of feeding a number of parallel optical data streams into a single fiber by utilizing compact on-chip wavelength-division multiplexing devices. The ability to multiplex large data streams at high data rates will allow future scaling of optical communications capable of delivering terabytes of data between distant parts of computer systems, according to IBM.

Interested in this technology! Attend this week's VLSI event IEEE International Electron Devices Meeting (IEDM), where the talk titled, “A 90nm CMOS Integrated Nano-Photonics Technology for 25Gbps WDM Optical Communications Applications.” going to be presented by Dr. Solomon Assefa.
Picture below: Cross-sectional view of an IBM Silicon Nanophotonics chip combining optical and electrical circuits
photonics chip

Picture below: Information super highways inside an IBM Silicon Nanophotonics chip.
light chip