Fig. 1. Schematic diagram of the［AlO_4/2］^- defects trapping a hole and becoming Al-OHC color center

Fig. 2. Schematic diagram of the［AlO_3/2］⁰ group becoming Al-E' color center by capturing electrons

Fig. 3. Schematic diagram of the atomic distribution of La-Er-doped fiber and normal Er-doped fiber

Fig. 4. Schematic diagram of the gain test system of erbium-doped fiber

Fig. 5. Online test results of S1 and S2

Fig. 6. Absorption spectra of S1 and S2

Fig. 7. Loss of S1 and S2 before and after irradiation

Fig. 8. Raman spectra of S1 and S2 before and after radiation irradiation

Fig. 9. EPR spectrum of S1 and S2 before and after irradiation

Fig. 10. Gain performance of S1 and S2 before and after irradiation