Manufacture cables with low losses

The use of monomode fibers with losses between 0.3 dB/km and 0.4 dB/km at 1.55 micron has made it necessary to design a cable structure which does not add to the losses of these fibers. The cylindrical V-grooved rod design protects the fiber from any stress and preserves its initial characteristics prior to cabling, even at 1.55 micron. This technology has made it possible to direct efforts towards the installation of 40 kilometer repeaterless links operating at bit rates of approximately 1 Gbit/s. This article first sets out to describe the structure of the 10-fiber cable and its manufacture. To minimize splice losses, it was decided to manufacture particularly long cable sections (2500 and 5000 meters). The second part of this article is devoted to the installation procedures for the different cable sections comprising a link between two cities in western France. Special pulling techniques were adopted to avoid applying excessive stress on the cables. The on-the-field splicing procedure of this fiber cable featuring the use of a carbon dioxide laser welding technique is then described. Lastly, results of measurements made over this link are presented and analyzed.