South African scientists working on ways to increase the bandwidth of communication systems have seen the light - and the results are dazzling. They have demonstrated more than 100 patterns of light in an optical communications link‚ potentially increasing the bandwidth of communication systems by a factor of 100.The discovery was made by a team at the University of the Witwatersrand in Johannesburg and the Council for Scientific and Industrial Research (CSIR)‚ which is looking at alternatives for when the rise of big data and advances in information technology mean that there is insufficient bandwidth using existing technology.The idea tested in their latest research - published on Friday in the scientific journal Scientific Reports - was conceived by Professor Andrew Forbes from Wits University‚ who led the collaboration. The key experiment was performed by Dr Carmelo Rosales-Guzman‚ a research fellow in the Wits School of Physics‚ and Dr Angela Dudley of the CSIR‚ an honorary academic at Wits.The project was based on the fact that as well as amplitude‚ phase‚ polarisation‚ colour and frequency‚ light has "patterns". These patterns can be used to encode information‚ and the team found that future bandwidth can be increased by precisely the number of patterns of light we are able to use.Existing optical communication systems use only one pattern‚ due to technical hurdles in how to pack information into patterns of light then get it out again.The Wits team used digital holograms on a liquid crystal display‚ demonstrating that it is possible to have a hologram encoded with over 100 patterns in multiple colours."This is the highest number of patterns created and detected on such a device to date‚ far exceeding the previous state-of-the-art‚" says Forbes.One of the novel steps was to make the device "colour blind"‚ so the same holograms can be used to encode many wavelengths.According to Rosales-Guzman‚ to make this work "100 holograms were combined into a single‚ complex hologram. Moreover‚ each sub-hologram was individually tailored to correct for any optical aberrations due to the colour difference‚ angular offset and so on".The next stage is to move out of the laboratory and demonstrate the technology in a real-world system."We are presently working with a commercial entity to test in just such an environment‚" said Forbes...