Radiation responses of Yb/Er-doped phosphosilicate optical fibers: hardening mechanisms related to Ce-codoping

In this paper, we investigated the origins of the Ce positive influence on the radiation response of Yb/Er-dopedphosphosilicate optical fibers. To this purpose, we carried out during γ-irradiations an online characterization on active optical fiber prototypes, made with different Ceconcentrations and integrated in optical amplifiers. The hardening effect of Ce-codoping is highlighted, as well as some aspects related to the radiation response of thephosphosilicate host glass of the active optical fibers.