Posted: 09th Sep, 2010 By: MarkJ

It's a little known fact that even "
super-fast" fibre optic broadband cables, especially those that run over very long distances (between countries), can suffer from performance loss due to unique forms of optical interference. Now scientists working at the
University of Southampton's Optoelectronics Research Centre (ORC) have developed a practical solution that could result in significantly faster fibre optic networks.
The new data transmission system, which is being developed as part of the EU-funded
FP7 PHASORS project, could potentially eliminate this problematic interference. The device essentially takes an incoming "
noisy data signal" and restores its quality, improving both the capacity and energy efficiency of the optical communication network.
The Problem (Contains Jargon)
Transmission of data through optical networks is currently limited by ‘phase noise’ from optical amplifiers and ‘cross talk’ induced by interaction of the signal with the many other signals (each at a different wavelength) simultaneously circulating through the network. ‘Phase noise’ is the rapid, short-term, random fluctuations in the phase of a signal, which affects the quality of the information sent and results in data transmission errors. ‘Cross talk’ refers to any signal unintentionally affecting another signal.
Reducing the build up of phase noise and also any amplitude noise might not seem important to most people, although improving the capacity of existing cross-border fibre optic cables (e.g. undersea cables) might help to make bandwidth cheaper. It's conceivable that such a benefit could also filter down to broadband ISPs and subscribers.
Indeed it is the very introduction of bandwidth-hungry video applications, such as popular web-based services like
YouTube, and the continued growth of the internet in general that has triggered this hunt for more efficient data signalling formats.
ORC Deputy Director and PHASORS Director, Professor David Richardson, said:
"Our regenerator can clean noise from incoming data signals and should allow for systems of extended physical length and capacity. In order to achieve this result, a major goal of the PHASORS project, has required significant advances in both optical fibre and semiconductor laser technology across the consortium.
We believe this device and associated component technology will have significant applications across a range of disciplines beyond telecommunications – including optical sensing, metrology, as well as many other basic test and measurement applications in science and engineering."
At present the device has already been tested using the fastest
commercial electronics, which can push data at rates of up to
40Gbps (Gigabits per second). However the novel solution could be used with networks that go much faster.