Characterisation of Raman gain spectra in Yb:YAG-derived optical fibres

Abstract

For the first time, Raman gain spectra are measured for three all-glass Yb:YAG crystal-derived optical fibres. It is shown that fibres derived from YAG have a reduced Raman gain relative to that of pure silica, partly because of a significant broadening of the silica Raman lines, and also partly because of yttria and alumina possessing a lower gain than that of silica. Such a designer-materials approach for suppression of stimulated Raman scattering can enable future high-energy and high-peak-power fibre laser systems. © 2013 Institution of Engineering and Technology.