Low-attenuation hollow-core fiber could herald more cost effective data centers and 5G networks
The Optoelectronic Research Centre (ORC) will announce the breakthrough in HCF technology at ECOC2018 in Rome, Italy.
Sep 26th, 2018
(Image: ORC) In hollow-core optical fibers, the conventional glass in the core is replaced by a gas or vacuum. These fibers, with a "holey" center, have attracted scientists owing to their faster light speed, giving less information delay -- important for data centers, 5G mobile communications, and driverless vehicles. Hollow-core fibers (HCFs) also have the potential for lower loss and higher data transmission capacity than conventional all-solid glass optical fibers. Despite predictions, the use of HCFs in optical communications has to date been severely limited by their relatively high optical loss. A breakthrough to be reported this week by the University of Southampton's Optoelectronic Research Centre (ORC; Southampton, UK) at ECOC2018 in Rome, Italy could herald the creation of larger and more distributed data centers and more resilient and cost-effective 5G networks. The postdeadline paper, "Record Low-Loss 1.3dB/km Data Transmitting Antiresonant Hollow Core fibre," is a joint initiative between the ORC, through the European Research Council (ERC) "LightPipe" project, and Lumenisity (Romsey, UK). It reports the world's lowest optical signal attenuation in a data-transmitting HCF. The result is particularly significant, as it breaks the previously recorded HCF attenuation level of 1.7dB/km, reported as long ago as 2004.* The results have been enabled by a novel fiber structure invented at the ORC** for which modeling predicts offers future losses as low as, or better than, standard silica fibers. The Nested Antiresonant Nodeless hollow-core fiber (NANF) developed by the Southampton team incorporates an arrangement of twelve carefully positioned glass capillaries with a wall thickness of just 1 µm. The tubes surround an empty central region and form a hollow pipe within which the light is guided. "[T]he experiments agree well with numerical simulations, giving us confidence in predictions that the capacity of the fiber could be increased by a further factor of two and the loss decreased by a factor of ten through design and fabrication improvements," says Professor Francesco Poletti of the Optoelectronics Research center Applications of this new technology will be explored in partnership with a range of academic and industrial project collaborators through the EPSRC-funded Airguide Photonics program. * B.J. Mangan, et al., Proc. OFC 2004, PD24. ** F Poletti, Opt. Express 22, 23807-23828 (2014). Source: ORC