Novel optical fibre uses topology approach

Applications and Research

Physicists at the University of Bath, UK, have developed a new kind of optical fibre designed to enhance the robustness of communications networks. They say that this robustness “could prove to be especially important in the coming age of quantum networks”.

The novel fibre deploys topological ideas by including several light-guiding cores in a fibre, linked together in a spiral. Light can “hop” between these cores but becomes trapped within the edge thanks to the topological design. These edge states are protected against disorder in the structure.

During optical transmission (usually by a laser or light-emitting diode) distortions in a fibre can cause the information to degrade as it moves between sender and receiver. “The challenge was to build a network that takes robustness into account,” said Physics PhD student Nathan Roberts, who led the research.

The team has fabricated optical fibres using the mathematics of topology. The modified fibres are easily scalable, meaning the structure of each fibre can be preserved over thousands of kilometres. The development and design is described in the latest issue of Science Advances.

should protect data communications, even when fibre is twisted or bent.

“Whenever you fabricate a fibre-optic cable, small variations in the physical structure of the fibre are inevitably present. When deployed in a network, the fibre can also get twisted and bent. One way to counter these variations and defects is to ensure the fibre design process includes a real focus on robustness. This is where we found the ideas of topology useful.”

For more information, visit www.bath.ac.uk