A teams of researchers from South Africa and Tunisia have demonstrated that adding light patterns to optical communications can bring significant bandwidth benefits. This new dimension in light encoding could potentially provide a hundredfold increase in the bandwidth offered by traditional optical communication systems.
Collaborators in the project include Professor Andrew Forbes, Dr Carmelo Rosales-Guzman, Dr Angela Dudley, and Bienvenu Ndagano from Wits University, South Africa; plus Professor Mourad Zghal, Dr Amine Ben Salem, and student Abderrahmen Trichili of Sup'Com, Tunisia.
Prof Forbes conceived the light patterns idea as an answer to the 'bandwidth ceiling' we are expected to hit in the near future. Currently optical communications systems "modulate the amplitude, phase, polarisation, colour and frequency of the light that is transmitted," explains Phys.org. Light patterns, simply how the light looks projected on a screen, add another dimension to the encoding. Current optical communications systems only use one pattern. The research team tested data transmission using 100 patterns of light and exploiting three degrees of freedom.
To make the new optical transmission method work "100 holograms were combined into a single, complex hologram," said Rosales-Guzman. Cleverly each sub-hologram "was individually tailored to correct for any optical aberrations due to the colour difference, angular offset and so on," added the optics researcher.
As usual, there need to be steps made to move this from a research project into a real-world system. That is the stated next stage of the project and lead researcher Prof Forbes says that negotiations are in process to test the system with a commercial entity.