Modeling the Radiation-Induced Attenuation Limits in Optical Fibers During Concurrent Irradiation, Thermal Annealing, and Photobleaching

The radiation-induced attenuations (RIAs) observed in optical fibers can be understood in terms of charge transfer and trapping rates using simple zero-field kinetic models. Herein, we analytically evaluate a one trap one recombination center (OTOR) kinetic model, wherein the primary trap state is actively thermally and/or optically bleached during the period of irradiation. Considering only the equilibrated system, we derive equations that describe the saturated trap concentrations in terms of the important experimental inputs: the radiation dose rate, the temperature, and the optical power. The equations are then reformulated in terms of saturation RIA values. Various optical fiber RIA data are extracted from the literature, wherein the aforementioned experimental inputs were varied. The derived equations describe these data with high fidelity in terms of the experimentally determined radiation dose rates, temperatures, and optical powers. Thus, we demonstrate a method through which high dose RIA values can be understood, modeled, and predicted under different experimental irradiation and bleaching conditions.