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 pre-loading 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 pre-treatment 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 increased with O2 presence. Data are analyzed in order to better understand the microscopic processes involved during the irradiation and to evaluate possible hardening developments.