title: In situ observation of the Yb2+emission in the radiodarkening process of Yb-doped optical preform.
abstract: This Letter relates the clear evidence of Yb2+formation under 2.5 MeV electron irradiation in optical fiber preforms showing a darkening of the core. We thus detected by in situ photoluminescence measurements the green emission of divalent Yb2+under the 355 nm excitation. Moreover, we showed the existence of two types of Yb2+ion species with different stabilities. We demonstrated that the radiodarkening mechanism is based on a pair association of Yb2+with aluminum oxygen hole center point defects.
authors.forename: N
authors.initials: N
authors.lastname: Ollier
authors.forename: C
authors.initials: C
authors.lastname: Corbel
authors.forename: J-B
authors.initials: JB
authors.lastname: Duchez
authors.forename: O
authors.initials: O
authors.lastname: Cavani
authors.forename: M
authors.initials: M
authors.lastname: Benabdesselam
authors.forename: F
authors.initials: F
authors.lastname: Mady