Optical analysis

Australian scientists have developed a system that can identify the causes of noise in the optical cables that form the backbone of the internet.

The system that the engineers at NICTA, Australia’s Information and Communications Technology (ICT) Research Centre of Excellence, have invented, will, for a few thousand dollars, do a job that today would cost over $100,000 and would require multiple types of test equipment.

It will allow phone companies to confidently increase the speed ratings on long haul optical fibres from 10 gigabits per second to 40 gigabits per second or more without losing data in the noise in line.

The six most common sources of signal impairments in fibre optical cable are caused by optical amplifier noise, too much dispersion as the laser beam travels down the fibre, a fibre that’s not quite symmetric – leading to more dispersion of the signal, power levels that are too high, interference from adjacent channels and unwanted reflections.