Index-matching of individual glass preforms: high-volume synthesis and high-precision refractive index measurements

We will present an overview on recent advances in high-volume synthesis starting from the powder-based concept of REPUSIL to create high-purity silica preform materials on demand. Emphasis is placed on precise index-matching of preform couples at defined level between each other, reaching an accuracy better than 5x10-5. The synthesized twin material will be used to fabricate fully aperiodic large pitch fibers (FA-LPF) to be used in lasers for material processing.