Transient and Steady State Radiation Responses of Solarization-Resistant Optical Fibers

We investigated the responses of several solarization-resistant (SR) multimode optical fibers to high dose-rate (> 100 Mrad/s), low dose-rate (5 krad/s) X-rays and very low dose-rate (0.3 rad/s) 1 MeV γ-rays. We characterized the radiation-induced attenuation (RIA) and radiation-induced emission (RIE) phenomena in the spectral range 200-1100 nm. These commercial fibers, optimized for the transport of high power of ultraviolet (UV) light, present good radiation tolerance to transient and steady state environments compared to other classes of multimode optical fibers with pure or doped cores (Ge, P, F). The different tested SR fibers present similar behaviors for both gamma-rays and X-rays. These fibers present low transient and permanent RIA levels for wavelengths greater than 300 nm. Our results showed that RIE can become an important factor of the fiber degradation, especially for high dose-rate irradiation. The induced losses in these fibers can be explained by the generation of Si-related defects like the SiE´, Si-NBOHCs or STHs and also to chlorine-related centers like Cl⁰.