Loss increases due to chemical reactions of hydrogen in silica glass optical fibers

Loss increases due to the chemical reactions of hydrogen are investigated for GeO
2
-doped, GeO
2
. F-doped, and pure silica core fibers. Dissolved hydrogen gas causes the hydroxyl loss increase as well as the short-wavelength loss increase in the first two fiber types at high temperatures. The short-wavelength loss increase is attributed to two kinds of ultraviolet absorption increases. Doping fluorine reduces both of these loss increases as well as enhances the activation energy of the hydroxyl formation.