Laurenz Kulmer of the Leuthold group will present the study at ETH Zurich during the Frontiers in Optics + Laser Science (FiO LS) conference, which will be held at the Colorado Convention Center in Denver from September 23 to 26, 2024.
High-speed free-space transmission is an option to connect the world, or it may serve as a backup if underwater cables break. 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.
Laurenz Kulmer, Leuthold Group, ETH Zurich
With their compact design, ability to operate at high speeds across a wide temperature range, and low energy consumption, plasmonic modulators are ideal for space communication links.
In outdoor free-space optical experiments, the researchers achieved data rates of up to 424 Gbit/s below a 25 % soft-decision forward error correction (SD FEC) threshold—the level at which errors in transmitted data can still be corrected despite noise or interference. In experiments using a plasmonic IQ modulator in a standard fiber system, an even higher throughput of up to 774 Gbit/s per polarization (pol) was achieved while maintaining the same 25 % SD FEC threshold.
Based on these results, the researchers suggest that combining coherent free-space optical communication with plasmonic modulators could significantly boost overall throughput, potentially reaching peak speeds of 1.4 Tbit/s. Their findings also show that operating free-space optical links at maximum speeds, as opposed to lower speeds and higher-order modulation formats, provides significant advantages.
The researchers further state that, with continued advancements in device design and photonic integration, it should be possible to achieve polarization multiplexing data rates exceeding 1 Tbit/s per polarization channel.
Kulmer concluded, “In a next step, we are going to test the long-term reliability of our devices. 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.”