A laser beam shot across a university campus may have just solved one of telecommunication’s oldest problems. 

Researchers at Wits University (South Africa) and the University of Bordeaux (France) have demonstrated a method to transmit optical data through open air without needing complex systems to correct for atmospheric distortion.

Sending data through open air has always been a messy thing. Earth’s atmosphere is chaotic. Swirling pockets of warm and cold air twist, scatter, and scramble light signals, often turning to heavy computing power and expensive adaptive optics just to piece the broken data back together.

Now, a world-first experiment laser shows we can simply ignore the distortion altogether.

The team successfully transmitted data through turbulent open air with its integrity entirely untouched. And it all came down to topology.

“We create and transmit these particle-like topologies of light through a 270-meter free-space optical link, revealing their robustness across a wide variety of conditions and turbulence strengths,” the study noted.

The coffee mug trick

Topology is a branch of mathematics concerned with properties that stay constant even when an object is stretched, twisted, or squished.

“To explain its benefits, we can liken it to how a coffee mug can be reshaped into the form of a doughnut,” said Prof Andrew Forbes, Head of the Structured Light Lab in the Wits School of Physics.

“Despite their very different shapes, both have a single hole. You can stretch or distort them without changing that fundamental property. In the same way, the light beam can become badly distorted while its topological information remains unchanged,” Forbes added. 

The team applied this concept to light, encoding information into exotic, particle-like magnetic structures called skyrmions. Encoding information into the light’s topological profile gives the data an invisible layer of armor, rather than relying on its raw brightness or color. 

To put the theory to the test, skyrmion-encoded laser beams were fired across hundreds of meters between two buildings on the Wits West Campus in Johannesburg. The light hit real-world heat, wind, and atmospheric noise.

When the light reached the receiver, the shape of the beam was utterly mangled. But surprisingly, the underlying topological data remained completely intact.

As a result, data was transmitted through the open air with over 98 percent fidelity in most conditions, dropping to only 86 percent under extreme turbulence.

Laser’s best possible use in space missions

Fiber-optic cables protect light signals by shielding color, intensity, and polarization from external disturbances. In contrast, sending unguided light through open air leaves these signals far more vulnerable to environmental disruptions like atmospheric turbulence.

Until now, free-space optical (FSO) communication systems required constant, real-time recalculations to undo the damage caused by the atmosphere. Receivers had to measure the distortion and fire off dynamic hardware corrections just to read a clean signal. 

But now, with this new approach, the topology survives the chaos. Therefore, the receiver can read the encoded payload directly without needing to clean up the beam first. 

And of course, the usage will be huge if scaled. Removing the need for heavy corrective hardware could lower the energy and computing demands for long-distance optical networks.

Particularly, the development could be beneficial in deep-space missions, high-speed satellite downlinks, and quantum cryptography. Closer to home, it might bridge the digital divide without laying miles of costly fiber-optic cable. The tech could soon give rural and isolated communities affordable, high-speed internet beamed straight through the sky.

The findings were published in the journal Science Advances.