What is silicon photonics?
- Dr. Mario Paniccia, Director of Photonics Research at Intel Labs (ComputerWeekly.com)
- A 50Gbps Silicon Photonics transmit module (ComputerWeekly.com)
Silicon photonics is an evolving technology in which data is transferred among computer chips by optical rays. Optical rays can carry far more data in less time than electrical conductors.
The concept involves combining laser and silicon technology on the same chip. The improved performance results from the greater available bandwidth and higher propagation speed of infrared (IR) beams compared with electric current. The effective implementation of silicon photonics technology would dramatically increase the processing speed and power of computers.
Silicon photonics research began in the late 1980s and has been ongoing ever since. Historically, one of the most serious challenges facing the developers of silicon photonics has been the fact that laser devices, which generate the IR beams that carry the data, are power-hungry. In addition, silicon has not proven effective for lasing because of thermal dissipation within the material. For these reasons, external lasers have been required in the manufacture of optical computers using silicon chips.
Researchers are developing methods of overcoming problems that prevent the use of silicon. For example, combining silicon with indium phosphide improves its IR-transmission capacity. Electric current is applied to the indium phosphide through metal electrodes, causing photon emissions that can be confined and concentrated in a silicon cavity, producing coherent IR.
Major researchers and chip makers such as Sun Microsystems, Intel and NEC are attempting to refine and deploy silicon photonics. In 2008, Sun received a government contract to explore further development. Intel has fabricated a chip containing a modulator that encodes data onto multiple IR channels at data speeds of 25 gigabits per second (Gbps) per channel. The ultimate goal is 40 Gbps.
Learn More About IT:
> Nanowerk highlights the advantages, limitations and applications of silicon photonics technology.
> Intel has published a white paper describing their silicon photonics effort.
> The Nanoscience Laboratory at the University of Trento (Italy) offers links to photonics-related technical papers.