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.