Combined FIB/SEM tomography and TEM analysis to characterize high aspect ratio Mg-silicate particles inside silica-based optical fibres

The evolution of particles, during the fabrication step of particle-containing glass fibres, was investigated. The aim of this study was to characterize quantitatively the composition, size and shape distribution of Mg-silicate particles within the initial silica-based preform and the final fibre, these information being crucial to better understand the mechanisms involved during the drawing step. A combined experimental approach using Scanning electron microscopy, Transmission electron microscopy and FIB/SEM tomography was implemented. The particle composition was found to stay unchanged during the drawing step. On the other hand, strong modifications of their shape within the fibre is observed and discussed.