Twin beams of light make fiberoptics better.

By about four times, BBC reports. Using double beams of light quadruples the data capacity of fiber-optic cables:

What limits the distance a given light signal can go is how much power is in the beam. But the higher the power, the more the light actually interacts with the material of the fibre, rather than merely passing through it.

That adds “noise” to the beam that limits the fidelity with which data can be transmitted.

What is needed is a way to undo this noise, and one idea is known as phase conjugation.

What Dr Liu and colleagues instead suggest is creating a pair of phase-conjugate beams, each carrying the same data.

And as Dr Liu explained to BBC News, the noise that each gathers is equally a mirror image of that on the other.

“At the receiver, if you superimpose the two waves, then all the distortions will magically cancel each other out, so you obtain the original signal back,” he said.

“This concept, looking back, is quite easy to understand, but surprisingly, nobody did this before.”

If the noise on the beams can be undone, the power can be ramped up – making data go literally further.