Different Er3 + environments in Mg-based nanoparticle-doped optical fibre preforms

•Structural study carried out directly on fibre preforms by using synchrotron sub-mm X-ray beams•Determined evolution of the Er3 + photoluminescence with the content of Mg in silica fibre preforms•Proposal of an unconventional method of analysis of EXAFS data for Er ions based on the Bond Valence Method•Links between the local structure and composition

Developing new rare-earth ion-doped optical fibres for power amplifiers and lasers requires continuous improvements in fibre spectroscopic properties. To overcome some limitations inherent to silica glass, it is proposed to embed rare-earth ions in dielectric nanoparticles. In this article we focus on the modifications of the Er3 + ion spectroscopy in Mg-silicate nanoparticles doped into optical fibre preforms. Through EXAFS and fluorescence measurements, we demonstrate that different local environments are experienced by Er3 + ions, attributed to the depolymerization of the phosphate network. These results gain insight into the tailoring of luminescence properties.