Laser Signal Transmission Tames Atmospheric Distortion

Researchers from the International Centre for Radio Astronomy Research (ICRAR) and the University of Western Australia (UWA) claimed a world record for what the team is calling the most stable transmission of a laser signal through the atmosphere. The work stems from a collaboration between the scientists from UWA and ICRAR with researchers at the French National Centre for Space Studies and the French metrology lab Systèmes de Référence Temps-Espace at Paris Observatory.

One of the self-guiding optical terminals on its telescope mount on the roof of a building at the CNES campus in Toulouse. Courtesy of ICRAR/UWA.

The team combined the phase stabilization technology of UWA, developed for the Square Kilometre Array telescope, with advanced self-guiding optical terminals. The combination enabled laser signals to be sent from one point to another without atmospheric interference.

According to Benjamin Dix-Matthews, a Ph.D. student at UWA, the technique effectively eliminates atmospheric turbulence.

“We can correct for atmospheric turbulence in 3D, that is, left-right, up-down, and, critically, along the line of flight,” Dix-Matthews said. “It’s as if the moving atmosphere has been removed and doesn’t exist. It allows us to send highly stable laser signals through the atmosphere while retaining the quality of the original signal.”

Because the transmission is uninterrupted by environmental factors, it holds potential in experimentation as an extremely precise method of comparing the flow of time between two locations.

“If you have one of these optical terminals on the ground and another on a satellite in space, then you can start to explore fundamental physics,” said ICRAR-UWA senior researcher Sascha Schediwy.

The technology also has potential application in optical communications due to its high stability.

“Our technology could help us increase the data rate from satellites to ground by orders of magnitude,” Schediwy said. “The next generation of big data-gathering satellites would be able to get critical information to the ground faster.”

The research was published in Nature Communications (www.doi.org/10.1038/s41467-020-20591-5).