Characterisation of doped sol-gel derived silica hosts for use in tunable glass lasers

Abstract

Measurements of laser-relevant properties of neodymium doped sol-gel derived silica hosts are described. Samples with Nd as the only dopant reveal anomalously short fluorescence lifetimes characteristic of concentration quenching TEM measurements revealing clumping of the neodymium. Co-doping with aluminium allows better dispersion of the neodymium throughout the gel-silica matrix, but fluorescence lifetimes and efficiencies are still lower than expected. Phonon quenching by residual OH^- ions is suspected, absorption, FTIR and Raman spectroscopy being used to support this theory.