Dispersion-compensating fiber and method of fabricating the same

摘要

This invention relates to a dispersion-compensating fiber which can be drawn at a lower temperature and can further reduce optical transmission loss. This dispersion-compensating fiber comprises a core portion containing a high concentration of GeO2 and a cladding portion formed around the outer periphery of the core portion. The cladding portion comprises a first cladding containing fluorine or the like as an index reducer, a second cladding having a higher refractive index than that of the first cladding, and a third cladding which becomes a glass region substantially noncontributory to propagation of signal light. In particular, the third cladding contains a desired impurity such that the glass viscosity thereof becomes lower than that of the second cladding or pure silica cladding at a predetermined temperature.