Bi co-doping for improving the ionizing radiation resistance of Er-doped fibers

Abstract

Three Er-doped fibers (EDFs) with different concentrations of Bi ions doping were fabricated by atomic layer deposition combined with modified chemical vapor deposition. The radiation-induced absorption (RIA) could be dramatically weakened by co-doping Bi. Especially, the RIA of Bi/Er co-doped fiber (BEDF) at 1300 nm was 56.0% lower than that of EDF after a 1500 Gy irradiation treatment. With the increase of the irradiation dose, the fluorescence intensity and lifetime of EDF decreased continuously, while BEDF showed a trend, increasing first and then decreasing, and changed little before and after irradiation. The gain characteristics and laser threshold power of BEDF are less varied than those of EDF before and after irradiation. In addition, an irradiation simulation model of EDF and BEDF fiber was established through GEANT4 simulation toolkit and found that Bi ions are more likely to absorb gamma rays, thereby reducing the impact of irradiation on Er ions in BEDF. These results indicate that Bi co-doped EDF has significant performance improvements in radiation resistance, making it ideal for applications in harsh radiation environments.