As humanity sends exponentially more data online, experts have voiced concerns that the world could soon run out of fibre optic capacity. Even though connection speeds are slowly creeping up in certain parts of the world, the worry is that we're eventually we're going to hit a limit of how fast fibre optic cables, AKA the "backbone of the Internet", can actually physically carry all that data.
But engineers from the University of California, San Diego in the US have smashed the current limit, by deciphering information that had been sent through fibre optic cables across a record-breaking distance of 12,000 km, without having to regenerate the signal. That means their signal was nearly 20 times stronger than our cables can currently handle.
Right now, when we send information over a certain distance, we need to use devices called 'repeaters' along the cable to convert the data into an electrical signal. This slows the system down and limits how much information can be sent, but it's necessary because our optical signals just can't handle that much power without being distorted an unrecognisable amount.
"Today's fibre optic systems are a little like quicksand," lead researcher Nikola Alic explains in a press release. "With quicksand, the more you struggle, the faster you sink. With fibre optics, after a certain point, the more power you add to the signal, the more distortion you get, in effect preventing a longer reach."
"Our approach removes this power limit, which in turn extends how far signals can travel in optical fibre without needing a repeater," he adds.
To avoid this distortion, which is known as 'crosstalk', the team first had to study it closely and map the interaction that occurred between the various channels of fibre optic cables. "Crosstalk between communication channels within a fibre optic cable obeys fixed physical laws. It's not random," says Alic. And this means they could learn how to predict it.
His team then created a 'frequency comb' - a device that predicts and reverses crosstalk - which allowed them to send 20 times stronger signals through fibre optic cables, without the need for regenerators.
Alic compares it to a conductor tuning up an orchestra at the start of a performance: by synchronising the starting point of the signals using the frequency comb, the team can ensure that they are deciphered without distortion on the other end, even if they've been blasted over 12,000 km.
The researchers now need to work on getting these frequency combs integrated into existing fibre optic cables. But once they do, they not only have the potential to make fibre optic cables more efficient and remove the 'speed limit' currently set on the Internet, but it could also greatly reduce the cost.
Now if only we could work out how to get fibre into more homes around the world so we can take advantage of this awesome research.