Japanese group claims largest transmission on standard multicore fiber

14 Aug 2017

Capacity of 118.5 terabits/s achieved with 125µm-diameter fiber – promising simple mass-production.

A consortium comprising Japan’s communications giant NTT and six R&D partners has demonstrated what it calls the world’s largest transmission capacity of 118.5 terabit/s over a multi-core fiber with four optical paths in the same diameter as current “standard” optical fiber.

The partners are KDDI Research, Sumitomo Electric Industries, Fujikura, Furukawa Electric, NEC and Chiba Institute of Technology.

A conventional glass fiber diameter is 125µm; agreed international standards enable users to effectively interconnect optical fibers and devices from different vendors – fiber and protective coating diameters are specified at 125±0.7µm and 235-265µm, respectively.

The Japanese group says the latest achievement proves the concept of a multi-core fiber-based long-haul and large capacity transmission system based on multiple vendor technologies, as well as making significant progress on the practical deployment of the multi-core fiber technology.

NTT commented, “We will aim to introduce this standard diameter multi-core fiber by the early 2020s. We will also continue to contribute the realization of a future optical infrastructure which can support variety of data communication demands.”

The result was first reported on 4 August as a post deadline paper at the Opto Electronics and Communications Conference (OECC 2017), the largest conference on optical communication in Asia Pacific-Rim, held at Sands Expo and Convention Centre, Singapore. The work was partially based on work commissioned by Japan’s National Institute of Information and Communications Technology.

Technical achievements

The project partners claim the following as achievements in the field of high-rate transmission over multicore standard fiber:

• Clarifying the design guidelines for a multi-core fiber with conventional glass diameter in accordance with international standards
• Realizing a multi-core transmission line composed of a standard diameter multi-core fibers fabricated by multiple vendors
• Proved a beyond-100 Tera-bit/s transmission using the standard diameter multi-core fiber transmission line.
• Developing a 316 km-long multi-core transmission line with a 0.21 dB/km average loss concatenating standard diameter multi-core fiber.

NTT concluded, “This achievement indicates that a multi-core fiber with the standard diameter can be used to realize a transmission capacity of more than 100 Tera-bit/s while enabling the productivity improvement and effective use of the existing technology. This achievement is expected to open up earlier practical use of the multi-core fiber technology.”