Faster internet due to breakthrough in fiber optic technology increasing bandwith

As rapidly increasing demand for bandwidth strains the Internet's capacity, a team of engineers has devised a new fiber optic technology that promises to increase bandwidth dramatically. The new technology could enable Internet providers to offer much greater connectivity, from decreased network congestion to on demand video streaming. The technology centres on donut-shaped laser light beams called ‘optical vortices’, in which the light twists like a tornado as it moves along the beam path, rather than in a straight line. Widely studied in molecular biology, atomic physics and quantum optics, optical vortices (also known as orbital angular momentum, or OAM, beams) were thought to be unstable in fiber, until BU Engineering Professor Siddhartha Ramachandran recently designed an optical fiber that can propagate them. In the paper, Ramachandran and Alan Willner of USC demonstrated not only the stability of the beams in optical fiber but also their potential to boost Internet bandwidth."For several decades since optical fibers were deployed, the conventional assumption has been that OAM-carrying beams are inherently unstable in fibers," said Ramachandran. "Our discovery, of design classes in which they are stable, has profound implications for a variety of scientific and technological fields that have exploited the unique properties of OAM-carrying light, including the use of such beams for enhancing data capacity in fibers," he added. The reported research represents a close collaboration between optical fiber experts at BU and optical communication systems experts at USC. "Siddharth's fiber represents a very unique and valuable innovation. It was great to work together to demonstrate a terabit-per-second capacity transmission link," said Willner, electrical engineering professor at the USC Viterbi School of Engineering. Ramachandran and Willner collaborated with OFS-Fitel, a fiber optics company in Denmark and Tel Aviv University. Funded by the Defence Advanced Research Projects Agency, the technology could not come at a better time, as one of the main strategies to boost Internet bandwidth is running into roadblocks just as mobile devices fuel rapidly growing demands on the Internet “For several decades since optical fibres were deployed, the conventional assumption has been that OAM-carrying beams are inherently unstable in fibres," said Ramachandran."Our discovery, of design classes in which they are stable, has profound implications for a variety of scientific and technological fields that have exploited the unique properties of OAM-carrying light, including the use of such beams for enhancing data capacity in fibres," he said. Ramachandran and Willner collaborated with OFS-Fitel, a fibre optics company in Denmark, and Tel Aviv University. Traditionally, bandwidth has been enhanced by increasing the number of colours, or wavelengths of data-carrying laser signals - essentially streams of 1s and 0s - sent down an optical fibre, where the signals are processed according to colour. An emerging strategy to boost bandwidth is to send the light through a fibre along distinctive paths, or modes, each carrying a cache of data from one end of the fibre to the other. Unlike the colours, however, data streams of 1s and 0s from different modes mix together; determining which data stream came from which source requires computationally intensive and energy-hungry digital signal processing algorithms.