Influence of hydrogen on optical fiber loss in submarine cables

Characteristics of the loss increase in optical fibers due to hydrogen permeation are described, and it is shown that the loss increase due to OH formation in GeO
2
-doped single-mode fibers is thought to be small compared to the loss increase due to the vibration of hydrogen molecules even in 20 years. Furthermore, the hydrogen generation due to electrochemical reaction in the optical cables is described. Finally, the countermeasure against the problem is discussed.