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Multiple wavelength laser helps silicon chip see the light


22 January 2010

The ultra-small revolution has begun with the invention of a new laser that will allow light to be used on a computer chip. Assoc. Professor David Moss, a senior researcher within the School of Physics and his international team have developed a multiple wavelength laser on a silicon chip that produces light to process and transmit information and in doing so will speed up computing.


CMOS compatible integrated multiple wavelength laser, reported by Moss and co-workers in the January 2010 issue of Nature Photonics. Device is based on parametric gain in an integrated 4-port ring resonator cavity with a Q-factor of 1.2 million, in high index doped silica glass.
CMOS compatible integrated multiple wavelength laser, reported by Moss and co-workers in the January 2010 issue of Nature Photonics. Device is based on parametric gain in an integrated 4-port ring resonator cavity with a Q-factor of 1.2 million, in high index doped silica glass.

"The on-chip light source will be key to enabling the simultaneous transmission of multiple data channels either on-chip or between chips in a single optical fibre, each at a different wavelength," says David, adding that this technology will ultimately provide the consumer with cheaper and faster computers.


"Currently information on a chip is shuffled around using electronic signals over copper wires, or interconnects. We know that metal is prone to 'choking' on the bandwidth bottleneck." David's paper* "CMOS-Compatible Integrated Optical Hyper-Parametric Oscillator", published in January in Nature Photonics (concurrent with a report from Cornell University on a similar device), says using light for simultaneous multiple information processing is an important breakthrough.


"With society's demands for even faster technology, ultrafast on-chip and chip-to-chip optical data communications are important. It's clear that more efficient methods to transmit vast amounts of data around circuit boards are needed to keep up with these requirements."


Though multiple wavelength sources are already known, the team has developed them on a chip that, in principle, can not only be integrated with silicon computer chips (i.e. CMOS) but can be also fabricated using the same methods. The device, based on high index doped silica glass, is low loss and has a high degree of manufacturability and design flexibility.


This makes it an ideal integrated multiple wavelength source not just to improve computing power, but for a wide range of applications including telecommunications, high-precision broadband sensing and spectroscopy, metrology, molecular fingerprinting, optical clocks, and even attosecond physics. David is based within the Institute of Photonics and Optical Science (IPOS) based within the School of Physics, The University of Sydney.


*"CMOS compatible integrated optical hyper-parametric oscillator" Nature Photonics4 41-44 (2010). L.Razzari, D.Duchesne, M.Ferrera, R.Morandotti - INRS, Montreal, Canada, B.E Little, S.Chu - Infinera Ltd., California, D.J Moss - The University of Sydney, Sydney, Australia