UK start-up to commercialise optical silicon

Si-Light, a spin-off of the University of Surrey, has received a grant from the DTI to bring its work into the commercial arena

A start-up formed by the University of Surrey has received a feasibility grant from the Department of Trade and Industry to commercialise its research on integrating optical components into silicon chips, a technology that could ultimately lead to faster, more power-efficient processors.

Si-Light, formed in order to exploit the university's breakthroughs in optical chip research, joins a growing list of companies seeking to use optical technology to break through some of the barriers facing chipmakers as processors grow more complex and powerful. STMicroelectronics last year announced it had developed a technique that could allow silicon chips to create a beam of light capable of carrying signals, while other research has focused on light-emitting nanotubes and other methods.

The start-up's technique is distinguished from those of competitors in that it is very stable, the company claims, and is compatible with the CMOS (complementary metal oxide semiconductor) process used to mass-produce inexpensive chips. In the near term, the firm's techniques could be used to drastically reduce costs for devices such as optical sensors, which ordinarily require the use of a silicon chip as well as an optical chip. Si-Light's technique would allow the optical processes to be integrated directly onto the silicon, the company claims. "It would allow the monolithic integration of the optical functions (with the silicon functions) on one substrate," said Dr Peter W. Epperlein, who is leading the feasibility project at Si-Light.

The firm's patented technology is based on research published by Dr Kevin Homewood and other University of Surrey scientists two years ago, using "dislocation engineering" to create a silicon-based light-emitting diode (LED). Since then the technique has been refined, and Si-Light was created to commercialise it.

Si-Light received the DTI SMART feasibility award earlier this year, but the grant was only publicly announced last week. The company, founded by Homewood and fellow University of Surrey academics Dr Russell Gwilliam and Dr Guosheng Shao, will use the award to establish partnerships with companies such as semiconductor makers, to which it can license its technology and consult on product development.

Merging optical technology with efficient silicon manufacturing techniques would solve pending problems facing both fields. Manufacturing optical components needs special techniques and more expensive materials than those used in mainstream silicon production. At the same time, while silicon chips are far less expensive to mass-manufacture, the very high density of transistors creates a great deal of heat and the very fast signals are difficult to route across circuits while being prone to interference. Photonics -- logic using light -- uses much less power, creates far less heat and has much more robust signals.

The Si-Light technique is not currently capable of creating the coherent light needed to carry a high bandwidth signal, but could prove more stable than the higher-voltage techniques which can do so, said Dr Epperlein. Many devices, such as optical sensors or "laboratories-on-a-chip" used to analyse gases or liquids, do not require the use of coherent light.

CNET's Michael Kanellos contributed to this report.