What if you could transmit a full HD movie from Shanghai to Los Angeles in less than five seconds using nothing more than the power of a night light? While that might sound like a scene from a science fiction novel, a team of Chinese scientists has made it a scientific reality. From a satellite stationed in orbit more than 60 times farther from Earth than Starlink, researchers have managed to deliver data at an astonishing speed of 1 gigabit per second, using a mere two-watt laser, no brighter than a candle flame.
Most modern satellite internet systems, like Starlink, operate a few hundred kilometers above the Earth and manage to push data at a few megabits per second. That may be acceptable for everyday streaming or web browsing, but it pales in comparison to the experiment recently completed by Chinese scientists. Their laser transmission, conducted from a satellite parked in geostationary orbit some 35,000 kilometers above Earth, reached a data rate five times faster than what Starlink currently offers, using a fraction of the power.
But this wasn’t achieved easily. One of the biggest challenges in laser-based space communication is the Earth’s atmosphere. As laser signals travel down from space, turbulence distorts and scatters them, turning once-focused beams into wide, fuzzy patterns by the time they hit the ground. These distortions often render laser links unstable and inefficient, particularly when using low-power sources.
Over the years, scientists have tried different methods to overcome this issue. Adaptive optics systems were designed to adjust the shape of the light wavefronts, correcting atmospheric distortion in real time. Separately, mode diversity reception, or MDR, was developed to detect and combine scattered light signals arriving through different spatial paths. While promising, neither technique was sufficient on its own under severe turbulence.
Led by Professor Wu Jian from the Peking University of Posts and Telecommunications and Liu Chao from the Chinese Academy of Sciences, the Chinese research team proposed a novel solution: combine both techniques into a single system. This approach, which they call AO-MDR synergy, works by first cleaning up the distorted signal using adaptive optics and then capturing the remaining scattered data through mode diversity reception. The result is a much stronger and clearer signal, even when passing through the chaotic conditions of Earth’s atmosphere.
The success of this method means that data can be transmitted reliably and quickly from much farther away than previously thought possible. Unlike satellite networks that rely on hundreds or even thousands of orbiting units, such as Starlink, this laser-based approach could provide global high-speed internet coverage using far fewer satellites. The potential for reducing congestion in low Earth orbit and cutting infrastructure costs is enormous.
If this technology continues to develop, it could revolutionize the way global communications function. From real-time data exchanges between continents to secure, high-bandwidth military communication systems, the applications are vast. Perhaps most intriguingly, it marks a departure from traditional thinking about power and distance, showing that with the right strategy, even a two-watt candlelight beam from space can outshine the most advanced systems on Earth.
