1 Department of Photonics Engineering, Technical University of Denmark2 University of Torino3 Swansea University4 iXFiber S.A.S5 Perfors6 Politecnico di Torino7 Swansea University8 Politecnico di Torino
A set of Ce-/Yb-co-doped silica optical fiber preform cores, differing in terms of dopant concentrations are studied by Electron Paramagnetic Resonance (EPR) spectroscopy before and after irradiation of the samples with excimer UV laser light and γ-rays. Evidence of Yb3+ clustering in the case of high Yb content samples is observed on as prepared samples regardless of the presence of Ce3+ ions. Si-E′ and Al-OHC centers were identified upon photon irradiation. The results are correlated to the micro-structural origin of the photodarkening process occurring in Ce–Yb doped glass fibers.
Journal of Non-crystalline Solids, 2014, Vol 403, p. 97-101