A world record for the most stable transmission of a laser signal through the atmosphere can be used to accurately test Einstein’s theory of General Relativity.
In a study published in the journal Nature Communications, Australian researchers from the International Center for Research in Radio Astronomy (ICRAR) and the University of Western Australia (UWA) partnered with researchers from the French National Center for Space Studies (CNES) and the French metrology laboratory Systèmes de Référence Temps-Espace (SYRTE) in the Observatory of Paris.
The team set the world record for the most stable laser transmission by combining Australians’ phase stabilization technology with advanced self-guided optical terminals. Together, these technologies allowed send laser signals from one point to another without interference from the atmosphere.
No atmospheric interference
Lead author Benjamin Dix-Matthews, an ICRAR and UWA PhD student, said the technique effectively eliminates atmospheric turbulence. “We can correct for atmospheric turbulence in 3-D, that is, left-right, up-down and, critically, along the line of flight, “he said.” It’s as if the moving atmosphere has been wiped out and doesn’t exist. It allows us to send highly stable laser signals through the atmosphere while preserving the quality of the original signal. ”
The result is the world’s most accurate method of comparing the flow of time between two separate locations. using a laser system transmitted through the atmosphere.
ICRAR-UWA principal investigator Dr. Sascha Schediwy said the research has interesting applications. “If you have one of these optical terminals on the ground and another on a satellite in space, then you can start exploring fundamental physics“he said.” Everything from testing Einstein’s theory of general relativity more precisely than ever, to discovering whether fundamental physical constants change over time.
The precise measurements of the technology also have practical uses in earth science and geophysics. “For example, this technology could improve satellite-based studies of how the water table changes over time, or to look for mineral deposits underground “, Schediwy said.
There are more potential benefits to optical communications, an emerging field that uses light to carry information. The optical communications they can transmit data securely between satellites and Earth at much higher data rates than current radio communications.
“Our technology could help us increase the data rate from satellites to the ground by orders of magnitude,” Schediwy said. “The next generation of big data collection satellites could get critical information to the ground faster“.
The phase stabilization technology behind the record link was originally developed to synchronize the incoming signals for the tSquare Kilometer Array scope. The telescope will be built in Western Australia and South Africa from 2021.