Influence of ${\hbox {O}}_2$ -Loading Pretreatment on the Radiation Response of Pure and Fluorine-Doped Silica-Based Optical Fibers

We investigated the impact of an oxygen preloading on pure-silica-core or fluorine-doped-core fiber responses to high irradiation doses (up to 1 MGy (SiO₂)). Oxygen enrichment was achieved through a diffusion-based technique, and the long-term presence of O₂ molecules was confirmed by micro-Raman experiments. Online radiation induced attenuation (RIA) experiments were carried out in both the pristine and the O₂-loaded optical fibers to investigate the differences induced by this pretreatment in the UV and visible ranges. Contrary to results recently published on the positive impact of O₂ on infrared RIA, our results reveal a RIA increase with O₂ presence. Data are analyzed in order to better understand the microscopic processes involved during the irradiation and to evaluate possible hardening developments.