Model for the dose, dose-rate and temperature dependence of radiation-induced loss in optical fibers

We propose, and verify in the case of a Ge-doped-silica-core optical fiber, a general explanation for the power-law dependencies on dose frequently observed for the radiation-induced attenuation in optical fibers. This insight permits detailed prediction of the post-irradiation recovery curves, given just the empirical exponent of the power law, 0<f<1, and the experimental irradiation time, t_irrad. The time constant of the recovery is given by t_irrad/(1-f), in both first-and second-order kinetics. We establish a microscopic model of radiolytic oxygen molecules for the γ-ray-induced absorption at 1.3 μm in our test fibers and infer a diffusion-limited bimolecular recombination process