A new type of optical fiber has 21 times more bandwidth than is available in existing communications networks, potentially cutting the impending “optical transmission capacity crunch” off at the pass. A team from Eindhoven University of Technology and the University of Central Florida developed the new fiber, which has seven cores instead of one, and was used to transmit 255 Tb/s — the existing standard is 4 to 8 Tb/s. The world is on the verge of reaching “the fundamental limit of single-mode fiber transmission capacity,” but seven-core fiber could satisfy growing demand for bandwidth, the researchers wrote in a study. The researchers used “few-mode multicore fibre, compact three-dimensional waveguide multiplexers and energy-efficient frequency-domain multiple-input multiple-output equalization” to demonstrate the viability of spatial multiplexing to reach a data rate of 5.1 Tb/s on a single wavelength over a single fiber. Combining this approach with wavelength division multiplexing featuring 50 wavelength carriers on a 50 GHz grid, the team achieved a gross transmission throughput of 255 Tb/s over a 1 km fiber link. “At less than 200 µm in diameter, this fiber does not take noticeably more space than conventional fibers already deployed,” said Eindhoven professor Dr. Chigo Okonkwo, adding that the study’s results could lead to even faster petabit-per-second transmission. The research was published in Nature Photonics (doi: 10.1038/nphoton.2014.243). For more information, visit www.tue.nl.