Gamma-ray radiation effects on hydroxyl absorption increase in optical fibers

Abstract
This paper presents gamma-ray irradiation effects on OH-loss increase due to the chemical reaction of H 2 for GeO 2 -doped and GeO 2 . P 2 O 5 -doped fibers. When H 2 diffuses into irradiated fibers (γ-H 2 treatment), OH-loss increase occurs even at room temperature. Moreover, OH-loss increases due to dissolved H 2 in irradiated fibers are larger than those in unirradiated fibers at high temperatures. These OH-loss increases are attributed to irradiation-induced defects with which H 2 reacts to form OH ions. When H 2 -dissolved fibers are irradiated, the OH-loss increases are larger than those in the γ-H 2 -treated fibers at room temperature. These larger loss increases are thought to be caused by the reaction of the unstable radical and dissolved H 2 , which are excited by the irradiation.