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Scientist who wires the world

In his latest Jewniversity column David Edmonds profiles Professor Polina Bayvel, who develops the technology that brings you the JC online - and much more

January 6, 2021 17:00
20171130_J-TYE_20171130_UCL_2253_BBC
3 min read

Every time you Zoom, stream a film from Netflix, scroll through Wikipedia, type a Google search or upload a photo of your kitten to Facebook, you have reason to be grateful to Polina Bayvel.

Professor Bayvel has devoted her life to making our optical communications system both faster and cheaper. It’s easy to forget how rapidly broadband has evolved. When the technique for guiding light energy along optical conductors was first proposed, in 1966, the British company involved boasted of its potential. They thought that, with time, it might be possible to transmit one gigabit of information per second. Many regarded these ambitions as hubristic. A gigabit has nine zeros. But today we can transmit 200 terabits; a terabit has 12 zeros. If you can’t get your head around that, I can aid you with the technical term — it’s known as “a heck of a lot”.

In response to the technical breakthroughs, there are now millions of miles of optical fibre cables both under the sea and below our feet on land. They’re the backbone of the entire digital communications infrastructure.

The key challenge in sending information through optical fibres is how to avoid the loss of light, or the data becoming corrupted, during transmission. Optical fibres are tiny rods of glass or plastic, very long, and about the width of a human hair. Information is transmitted as follows. First it’s turned into light pulses, then it’s sent along the fibre, bouncing off the tube as it travels. The further the light journeys, the more likely things are to go wrong. Polina Bayvel’s lab researches the whole infrastructure involved in the process — not just the cables, but discovering, for example, that you could put multiple wavelengths down a single fibre, rather than just one. Her team also investigates how best to use amplifiers, to give light pulses a kick up the backside whenever there’s a danger of their becoming too weak to go on. A puzzle they want to crack in the future is how to make the whole system more “intelligent” so that it can predict and respond to periodic bouts of high demand in different places.