With a significant growing interest and investment from government and private agencies, space exploration appears to be an ever-widening field.
However, large distances pose quite a challenge in explorations. As space missions gather large amounts of scientific data, measurements, and images, high-speed free-space data transmission could improve connectivity for space missions.
Researchers at ETH Zurich have accomplished a significant leap in high-speed data transmission, as high as 424Gbit/s across a 53-km turbulent free space optical link. As a Gigabyte is equal to 8 Gigabits, 424Gbit/s is equivalent to 53GB/s.
Scientists have been trying to use photons (light) for data transmission for a while now. This data transmission, too, uses plasmonic modulators. Plasmonic modulators use special light waves called surface plasmon polaritons to control and change optical signals.
Plasmonic modulators have emerged as ideal candidates for space communication links because they are compact and can operate in a wide temperature range with low energy consumption.
“High-speed free-space transmission is an option to connect the world, or it may serve as a backup if underwater cables break,” said Kulmer. “Nevertheless, it is also a step towards a new cheap high-speed internet that may connect all locations across the world. This way it may contribute towards a stable, high-speed internet for millions of people who are currently unconnected.”
Free-space optical communication networks could offer high-capacity data transmission with lower latency and less interference than traditional radio frequency communication systems. This could be a breakthrough in allowing real-time conversations between astronauts.
During the testing, researchers achieved data transmission rates of up to 424 Gbit/s below a 25% SD FEC threshold. Also, the plasmonic IQ modulator in a standard fiber system enhanced the throughput up to 774 Gbit/s/pol while staying below a 25% SD FEC threshold.
“In the next step we are going to test the long-term reliability of our devices,” said Kulmer. “High-speed performance has been shown, but we have to make sure they can operate for years to come in the harshest of environments, space.”
Researchers say that by using plasmonic modulators with coherent free-space optical communication, speed can even reach 1.4 Tbit/s.
