Fig. 1. Construction of high power Yb-doped fiber laser based on MOPA structure

Fig. 2. The model of radiation-induced color center of the Yb³⁺-doped fiber

Fig. 3. Illustration of suppressing the hole-related color center by H₂ loading treatment

Fig. 4. Influence of (a) doped fiber length and (b) pump structure on the EDFA’s radiation properties; (c) comparison of the EDFA’s radiation properties with and without the optimized parameters

Fig. 5. Variation of gain versus total radiation dose of three different doping fibers

Fig. 6. Variation trend of the amplifier under different dose and different system parameters

Fig. 7. (a) Output power and (b) irradiation loss vs irradiation dose under 915 nm and 976 nm pump

Fig. 8. Properties variation of (a) combiner and (b) cladding pump stripper before and after radiation

Fig. 9. Slope efficiency under different total radiation dose

Fig. 10. Output power and STD versus pump power of pristine, γ irradiated and 532 nm bleached fibers

Fig. 11. Output power of the fiber laser at different wavelength under diffevent pump

Fig. 12. (a) Variation of TMI versus radiation dose and (b) the output power profile and TMI area under different radiation dose

Fig. 13. Comparison of properties under different radiation dose between Ce doped fiber and commercial fiber