Military and civil authorities could benefit from secure optical communication systems that use light to carry messages between moving vehicles.
Researchers at King Abdullah University of Science and Technology-KAUST have now demonstrated rapid data transfer using ultraviolet-B (UV-B) light, which provides many advantages over visible light.
This is where UV-B becomes useful. UV-B from the sun is mostly absorbed by ozone in the upper atmosphere, so it doesn't interfere with communication.
Optical communications systems using visible lasers and light emitting diodes (LEDs) suffer from interference due to the high levels of visible light in sunlight. What's more, the transmitter and receiver must be aligned very precisely, which is very difficult for vehicles on the move.
PhD student Xiaobin Sun worked on the project with professors Boon Ooi and Slim Alouini from the Department of Computer, Electrical and Computational Science and Engineering, alongside other coworkers at KAUST and the Chinese Academy of Sciences in Beijing.
"Accurate beam alignment for point-to-point (or line-of-sight) optical communication is challenging-slight movements of just a few millimeters might break the communication link. This problem motivates us to look for a nonline-of-sight communication system," said Sun.
Sun, Ooi, Alouini and coworkers are developing high-performance UV-LED sources and highly sensitive detectors that receive UV signals quickly and accurately.
Commenting on their achievement, Ooi said: "Other groups have used different types of UV sources for transmitting relatively slow NLOS signals for communications. We are the first to achieve multiple tens of Mbps transmission using UV-B LEDs."
Now that KAUST scientists have proven their concept in a low-power system, the team plans to increase the optical power and sensitivity until they achieve long-distance nonline-of-sight UV communications with high data transmission rates.
"These collaborative efforts between the photonics and communication theory groups at KAUST are paving the way toward the next frontier for optical wireless communication systems," says Alouini.
