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Satellite

1 Gbps Laser Link from 36,000 km Orbit Outpaces Starlink

Author: auto.pub | Published on: 18.06.2025

Chinese scientists have pulled off a major breakthrough in satellite communications, successfully transmitting data at 1 Gbps from a geostationary satellite orbiting 36,000 kilometers above Earth—five times faster than Starlink, which operates from a much closer 550-kilometer orbit. The kicker? They did it using a laser no more powerful than a candle, just 2 watts.

Despite the massive distance and the chaos of atmospheric turbulence, researchers managed to maintain a stable connection thanks to a new technique dubbed “AO-MDR synergy,” developed by teams at Beijing University of Posts and Telecommunications and the Chinese Academy of Sciences. The method merges adaptive optics (AO), which corrects distorted light, with multi-diversity reception (MDR), which captures scattered signals. Together, they counteract the degrading effects of weak signal strength.

Testing took place at the Lijiang Observatory in southwestern China, where a 1.8-meter telescope locked onto a satellite hovering 36,705 kilometers away. The telescope is equipped with 357 minuscule micromirrors, each independently adjustable. These are the backbone of the adaptive optics system, actively reshaping the incoming laser beam distorted by Earth’s atmosphere. Once corrected, the beam is funneled into a multimode optical fiber and split into eight foundational channels using a multi-plane light converter (MPLC).

A real-time “path selection” algorithm then determines which three of the eight channels are delivering the strongest, most coherent signals. This filtering significantly boosts signal clarity and stability—a claim backed by repeated experimental trials.

The primary gain? A dramatic drop in transmission errors. The percentage of “usable signals” jumped from 72 to 91.1 percent. In practical terms, that could mean less buffering, pixelation, and lost frames during HD video streams—a smoother and more stable experience overall.

While conventional radio communications are brushing up against their technical ceiling in terms of bandwidth, laser-based transmission offers a much wider channel for faster, more efficient data delivery. For now, China’s achievement shows that even from the edges of space, a whisper of light can carry a thunderclap of information.