Overview of Radiation Effects on Silica-Based Optical Fibers and Fiber Sensors

This review focuses on silica-based optical fibers (OFs), guiding light through the total internal reflection (TIR) mechanism, that are currently used in telecommunications and sensor networks. This review briefly introduces the fiber and fiber sensor technologies. This review presents their various applications in radiation environments. The radiation effects on OFs are explained: first, at a microscopic scale, with the description of point defects generated by irradiation. Then, the macroscopic consequences of the appearance of these point defects are discussed: in particular, the phenomena of radiation-induced attenuation (RIA), radiation-induced emission (RIE), and radiation-induced refractive index change (RIRIC). RIA impacts nearly all applications under irradiation. We then detail the various parameters, intrinsic or extrinsic, of OFs which influence their amplitudes and kinetics. This improved knowledge paved the way for the radiation hardening of OFs through various approaches, either at material, component, or system levels. Recent advances are presented for passive and active rare-earth doped OFs and systems. Then, the use of fiber-optic sensors is introduced, with the latest advances in radiation-hardened point or distributed sensors. Then, the potential of this technology for radiation detection, beam instrumentation, and dosimetry applications is assessed. Finally, the future prospects and the main challenges to be met to accelerate the implementation of this technology in the harshest environments are discussed.