In a major development for space-based laser communication, Chinese scientists have successfully transmitted data from a high-orbit satellite to Earth at a rate of 1 gigabit per second (Gbps). This impressive breakthrough was achieved using an exceptionally low-power 2-watt laser, marking a significant advance for the technology.

The experiment utilized a satellite positioned in a geostationary orbit approximately 36,705 kilometers from Earth. For comparison, this is more than 60 times higher than the orbits of Starlink satellites, which operate just hundreds of kilometers above the planet. The achieved data-transfer speed is also reportedly five times faster than Starlink's typical performance.

The big difference between this and other laser-based satellite technology is that this is using low-power lasers between the satellites and Earth, rather than high-power lasers between different satellites.

Overcoming Atmospheric Hurdles

One of the main challenges for satellite laser downlinks is atmospheric turbulence, which can scatter and weaken the light signal, making data transmission unreliable. Previous methods to counteract this, such as adaptive optics (AO) or mode diversity reception (MDR), have had limited success on their own under strong turbulence.

To combat this signal disruption, researchers from the Chinese Academy of Sciences and Peking University of Posts and Telecommunications devised an innovative hybrid system. Their new "AO-MDR" method merges the two previously distinct techniques. According to their findings, this combined strategy stops communication quality from deteriorating, even when faced with very weak signals. The result was a dramatic improvement in the reception of usable data, jumping from a 72 percent success rate to more than 91 percent. (Source: slashgear.com)

Advanced Ground Systems

The test was conducted at an observatory in Lijiang, China, using a 1.8-meter telescope to receive the laser signal from the distant satellite. The system incorporates 357 micro-mirrors that actively reshape the distorted laser light to reduce interference caused by its journey through the atmosphere. (Source: scmp.com)

An advanced converter splits the incoming light into multiple channels, and a specialized algorithm selects the strongest signals to merge in real time. Think of it like sending multiple copies of Mike Teavee (from Charlie and the Chocolate Factory, circa 2005) rather than merely breaking him into small pieces.

What's Your Opinion?

Do you think laser-based communication will eventually replace radio waves for satellite Internet? What are the potential advantages of having high-speed communication from geostationary satellites? How might this technology impact global Internet connectivity in the coming years?