Large volume manufacturing of dispersion compensating fibers

Summary form only given. We report results of large volume production of more than 10000 km of dispersion-compensating fibers (DCF). This is equivalent to more than 1000 modules, which each can compensate 60 km of standard fiber. Reproducible large volume production of DCF is a difficult task. The design is very sensitive towards small variations in the index profile. For example, we find for our design that a 1% variation of either the core diameter or core index results in a change in dispersion of 5 and 2.5% respectively. Another challenge is to obtain low polarization-mode dispersion (PMD). DCF is more than one order of magnitude more sensitive to core ovalities than conventional telecommunication fibers due to the high core index used. Therefore extreme care has been taken to avoid core ovalities. At the same time we stimulate the mode coupling by introducing oscillatory twist into the fiber during draw. Enhanced mode coupling not only reduces the PMD, but also gives a more stable PMD value, for example during temperature cycling of DCF modules.