As data network traffic has grown due to the widespread use of smartphones and other applications, there has been an increasing demand for optical communication systems that have a large transmission capacity. To deal with this demand, a new optical transmission system applying digital coherent technology*2 has been increasingly introduced, however, optical fibers used for this technology need to have low transmission loss and large effective core areas (the cross-section areas where light propagates).
Sumitomo Electric developed low-loss pure-silica core optical fibers and has since supplied its “Z Fiber,” “Z-PLUS Fiber” and other advanced fiber products widely to submarine optical cable industries. Recently, the Company has developed optical fibers with the world’s lowest transmission loss of 0.149 dB/km at 1550 nm by leveraging its newly developed loss reduction technology and mass production technology accumulated through the 20 years of pure-silica core optical fiber manufacturing. Sumitomo Electric has thus succeeded in breaking its own world record of the lowest transmission loss for the first time in 11 years.
Following this achievement, the Company is going to release two optical fiber products in April 2013: “Z-PLUS Fiber ULL” with a typical loss of 0.154 dB/km (improved from 0.16 dB/km of “Z-PLUS Fiber”) and “Z-PLUS Fiber 130 ULL” with a typical loss of 0.154 dB/km and an effective core area 1.6 times larger than that of a standard optical fiber to deal with high input signal power.
These two products are best suited to digital coherent transmission that has been increasingly introduced for high-speed large-capacity data communication such as ≥100Gbit/sec system. These optical fibers are highly expected to increase transmission capacity and transmission distance, while also saving system costs by reducing the number of expensive optical repeaters to be used in submarine optical cable systems.
Sumitomo Electric will continue to work on the development of high-performance optical fibers with the aim of contributing to the advancement of large capacity transmission technology.
This achievement was presented in the post deadline paper of the OFC/NFOEC 2013*3, a major exhibition in the optical communication industry held in Anaheim, USA and reported in detail in the following session.
- “Z Fiber” and “Z-PLUS Fiber” are trademarks or registered trademarks of Sumitomo Electric Industries, Ltd.
- *1 Transmission loss refers to the amount of light degraded by scattering and absorption while traveling in an optical fiber. With a lower transmission loss, optical signals can be transmitted for a longer distance. Z-PLUS Fiber boasts a transmission loss of 0.16 dB/km at 1550 nm, which is the lowest loss among commercial optical fibers.
- *2 Digital coherent technology uses lightwave properties of optical signals (phases) to transmit/receive the optical signals. This technology offers transmission capacity ten times larger than the conventional transmission technology that uses the on/off patterns of optical signals.
- *3 M. Hirano, T. Haruna, Y. Tamura, T. Kawano, S. Ohnuki, Y. Yamamoto, Y. Koyano, and T. Sasaki, “Record Low Loss, Record High FOM Optical Fiber with Manufacturable Process,” PDP.A5.7., OFC/NFOEC 2013, Anaheim, CA, (2013).