Impact of Al₂O₃ doping on Bi active center photobleaching in Bi/Er-codoped fibers

In this Letter, the impact of Al₂O₃ doping on the Bi active center (BAC) photobleaching is investigated in Bi/Er-codoped fibers (BEDFs). By measuring the evolution of emission attributed to the BAC associated with silica (BAC-Si) at ∼1400nm, the linear relationship between the ratio of unbleached/bleached part (γ/γ_B) and 830 nm irradiation intensity (P₈₃₀) was revealed in the log-log plot. The experimental results demonstrate that Al₂O₃ doping or its induced defects could be one key factor exaggerating the BAC photobleaching in BEDFs.