Influence of oxygen deficiencies and hydrogen-loading on defect luminescence in irradiated Ge-doped silica glasses

The influence of ionizing radiation on the optical properties of various Ge-doped silica glasses in the UV-vis range was examined. Hydrogen-loaded and hydrogen-free germanosilicate glass samples containing varying amounts of oxygen deficiencies were X-ray irradiated and changes in their respective absorption and luminescent properties were measured. The results show that germanium oxygen deficient centers (GODCs) are necessary for significant absorption changes in the hydrogen-free samples. In the hydrogen-loaded samples, large absorption changes were observed in the 200-550 nm range regardless of GODC content. Emission bands at 615 and 680 nm were also found to result from irradiation in these samples. Furthermore, it was found that X-ray radiation drastically increased the concentration of germanium lone pair centers (GLPCs) in H2-loaded samples with low initial GODC concentration