适用于强辐照环境的多模传能光纤性能退化研究OA

[Background]Power-delivery optical fibers are used to route high-power laser beams in radiation environments.Under high total ionizing dose(TID),radiation-induced point defects increase attenuation at the operating wavelength and enhance heat generation,leading to thermal buildup and reduced operating margins.[Purpose]This study focuses on a pure-silica step-index multimode power-delivery fiber and aims to evaluate the effects of 60Co γ irradiation on its near-infrared transmission performance,the evolution of irradiation-induced point defects,and the temperature response under high-power operation,thereby elucidating the link between defect formation and macroscopic performance degradation.[Methods]RIA spectra were measured for fiber samples irradiated to multiple total doses.Under high-power transmission,the output power and temperature rise of an unirradiated fiber and a 100-kGy-irradiated fiber were compared at identical pump settings to quantify irradiation-induced macroscopic degradation.Electron paramagnetic resonance(EPR)and photoluminescence(PL)measurements were performed to microscopically identify the generation and transformation of irradiation-induced point defects.[Results]RIA increases overall with dose,and the additional attenuation at the 1 080 nm operating wavelength rises markedly.The transmitted output power decreases by 0.5%-4.3%after irradiation and is accompanied by a pronounced temperature increase,indicating that irradiation-induced excess loss is more readily converted into thermal load during operation.EPR shows a monotonic accumulation of E′ paramagnetic centers,while PL exhibits oxygen-vacancy-related emission peaks that increase and then decrease with dose.Taken together,the results show that at high doses,oxygen-vacancy-related luminescent centers undergo charge-state redistribution and conversion toward non-radiative centers,such as E′,leading to concomitant enhancement of excess loss and heat accumulation.[Conclusions]These findings provide mechanistic interpretation and experimental evidence to support performance-degradation assessment and radiation-hardening design of power-delivery fibers for nuclear decommissioning,spent-fuel processing,and other radiation-intensive applications.