X-ray irradiation effects on a specific multistep Ge-doped fiber

Abstract : The study of point defects generation in optical fibers plays an important role with regards to their use and application in different domains. Their design and elaboration processes (dopants type, concentration, refractive index profile, drawing conditions...) govern their responses and more generally their radiation hardness [1]. In this work we investigated, the influence of 10 keV X-ray irradiations on a set of specific germanosilicate optical fibers elaborated from the same preform at different drawing conditions. The germanium doping levels along the fiber core diameter was specifically designed to follow a two-step distribution in order to highlight the Ge-concentration effect and more generally its influence on the Ge-defects formation such as the Germanium Lone Pair Center (GLPC) [2], or more generally on the generation of other centers such as the Non Bridging Oxygen Hole Center (NBOHCs).