MECHANISMS OF HYDROGEN-INDUCED LOSSES IN SILICA-BASED OPTICAL FIBERS

The mechanisms of hydrogen reaction with a glass structure were studied and found to be divided into two groups. One was responsible for the reaction with glass networks, not defect centers, by which the increases of the short-wavelength loss edge (SLE), hydroxyl group (OH), and long-wavelength loss edge (LLE) were caused at elevated temperature. The second group is proposed to be the reaction with diamagnetic defect centers (=Si:), which are induced by the drawing process and cause excess absorption at 0.63 µm. The room-temperature reaction causes the growth of OH and the generation of an absorption peak near 1.52 µm. © 1990 IEEE