Polina Bayvel, Professor of Optical Communications, at UCL, and her team have just set a new speed record for sending data over real-world optical cable. They managed to send about 10 times more data than the best commercial services. Remarkable this was without changing the cable or other core infrastructure: the record was set over existing fiber running through a city centre with all the interference that causes, and with all the grime, wear and tear that comes with real use.
What was the secret? Commercial fibre optics typically use wavelengths of 850, 1300 and 1550 nanometers. That is infrared light, which some animals can see, including some snakes, fish and insects (and vampire bats). However, we need special cameras that convert it to the visible range before we can see infrared. What we can do though is create lasers that send pulses of infrared at these wavelengths. We can also design hardware that turns infrared pulses back into data. Polina’s team developed special hardware that could send data over a much larger range of frequencies of light than the existing commercial systems. It used a range of wavelengths of light between 1264 and 1618 nanometers. By mixing these higher wavelengths together they could send more data at the same time – but that is only useful if their hardware could extract the separate signals from the mixed up mess of them, back at the end. The test showed that their hardware could do that in the real-world conditions of sending data from their lab in central London out to a data centre at Canary Wharf over the existing cables, and back, so around 10 miles in total.
It means that in future we will be able to send far more data over existing cable networks with no need to replace the cables, so avoiding the extra time and costs (never mind the road works). The speed of 450 terabits per second is enough to stream 50 million films at the same time. No one actually needs to do that of course. However, our technologies do seem to voraciously use up whatever capacity we create, and with the ever-increasing use of AI tools and their need for masses of data, it may well be this ability to send more data is needed sooner than we might think.
Paul Curzon, Queen Mary University of London
More on …
- The optical Pony Express (more on Polina Bayvel’s work)
- Networks and Telecommunications
- Women in computing
- New Scientist: New fibre-optic record allows 50,000,000 movies to be streamed at once [EXTERNAL]
Subscribe to be notified whenever we publish a new post to the CS4FN blog.
cs4fn 