Effects of molecular hydrogen on low-intensity UV photochemistry of germanosilicate glasses.

Germanosilicate glasses are known to posesses photorefractive (photosensitive) properties [1], that allows to fabricate refractive index gratings in germanosilicate optical fibers [2]. Hydrogen loading silica and germanosilicate glasses enhances its photosensitivity significantly [3-6]. Since the germanium-oxygen deficient center (GODC) is the main photosensitive defect in germanosilicate glasses, it is of particulary importance to reveal the role of molecular H2 in the processes of GODC phototransformation. In this work, we study the influece of molecular hydrogen impregnated into the glass network on the triplet decay time τT, luminescence intensity (T1 - S0, λmax=397 nm) and efficiency of GODC photodecay when excited with low-intensity UV light.