Germanium-dopant effect on hydroxyl loss increase in optical fibers

The germanium-dopant effect on hydroxyl loss increase in optical fibers is studied experimentally. The distribution profile of hydroxyl absorption which is caused by hydrogen diffusion is measured for GeO
2
-doped silica glasses. From the experiment, it is found that the distribution profile of induced hydroxyl absorption is similar to the GeO
2
concentration profile. Moreover, the absorption loss increases due to hydrogen diffusion are measured for GeO
2
-doped silica fibers. From the experiment, it is concluded that the induced molecular hydrogen loss as well as the induced hydroxyl loss increases with an increase in the GeO
2
concentration.