A new twist on broadband communications

Guglielmo Marconi (1874-1937)

A year ago, my old space physics collaborator Bo Thidé and his colleagues in Uppsala and elsewhere published a series of papers, one of which appeared in the prestigious journal Nature Physics, along with a commentary by an independent expert. The astrophysics paper by Fabrizio Tamburini and others is concerned with the twisting of light waves around rotating black holes, but much of the wider discussion has to do with the practical engineering implications for future communications technologies.

Tamburini’s atsrophysics paper received a fair amount of popular press attention, but it is the applied physics work on radio wave vorticity and orbital angular momentum which is likely to have a direct impact on our everyday lives. At the same time as Tamburini’s article was published, a related paper with Thidé as first author discussed the potential of using twisted radio beams to carry more information than is possible with WiFi and other existing broadband technologies.

A new paper, again with Tamburini as first author, has just appeared, with a focus on encoding multiple communication channels on the same frequency through radio wave vorticity. Unlike the previous work, which was largely theoretical, the new results are based on real-world experiments with two beams of radio waves, transmitted on the same frequency but encoded in different orbital angular momentum states. With this configuration, the researchers show how one could in principle implement an infinite number of communication channels within a fixed bandwidth.

The BBC’s Jason Palmer has provided us with a clear introduction to the science of radio wave vorticity and its practical potential. Palmer’s reference to Guglielmo Marconi‘s pioneering work on radio communication is apposite, and echoes the opening paragraph of Tamburini’s latest paper. Twisted radio beams could facilitate another revolution in wireless communication.