NBN take note. Scientists in the UK have demonstrated a new data transmission system that could substantially improve the data transmission capacity and energy efficiency of fibre optic networks running over long distances.
According to researchers working on an EU-funded project at Southampton University, the transmission of data through optical networks is currently limited by interference from signals known as ‘phase noise’ and ‘cross talk’ which stretches the limits of long distance fibre networks.
‘Phase noise’ is the rapid, short-term, random fluctuations in the phase of a signal, which affects the quality of the data sent and results in transmission errors. ‘Cross talk’ refers to any signal unintentionally affecting another signal.
Current fibre technology sends optical data as a sequence of bits that are coded in light beams, a system that is simple and practical but inefficient in its use of bandwidth.
Until recently, this wasn’t a problem given the enormous data-carrying capacity of an optical fibre. However, bandwidth-hungry video applications, such as YouTube, and the continued growth of the internet have led to increasing calls for more efficient data signalling formats.
The team, led by the University of Southampton’s Optoelectronics Research Centre (ORC), say their new device – a phase sensitive amplifier and phase regenerator for high-speed phase encoded signals – could potentially eliminate interference from signals.
Using advances in both optical fibre technology and lasers, the prototype plug-in device eliminates the phase noise directly, unlike others developed in the past, without the need for conversion to an electronic signal, which would inevitably slow the speeds achievable. It takes an incoming noisy data signal and restores its quality by reducing the build up of phase noise and also any amplitude noise at the same time.
Deputy Director of Southampton University’s Optoelectronics Research Centre (ORC), Professor David Richardson said: “Our regenerator can clean noise from incoming data signals and should allow for systems of extended physical length and capacity. [It] has required significant advances in both optical fibre and semiconductor laser technology across the consortium.”
The device has been developed using expertise from the UK, Sweden, Ireland, Greece, Switzerland and Denmark.
