Numerical Modeling of Bi-Doped Phosphosilicate Fiber Amplifiers

The potential of Bismuth (Bi) to amplify optical signals in wavelength bands not covered by rare-earth (RE) elements makes it the best candidate as an active medium for silica fibers, to expand optical communication capacity beyond the C+l bands [1], [2]. Even if Bi-Doped Fiber Amplifiers (BDFAs) have shown promising performance in the O, E and S bands [1]–[3], leveraging the ultrabroadband emission of Bi-related active centers (BACs) formed in different silica glass hosts, further optimization is needed. However, existing numerical models based on rate equations for RE-doped fibers fail to fully account for the complexities of BACs, leading to lack of accuracy.