Suppression of photo-darkening effect by Ca additive in Yb-doped silica glass fibre

Abstract

It is found that Ca additive effectively suppresses the photo-darkening effect in Yb-doped silica fibre even at 6.0 wt% of high Yb2O 3 concentration. Ca ion works as a stabiliser to maintain the Yb 3+ valence state. It is hypothesised that this phenomenon may reflect the local charge balance effect in silica glass. This Yb-Ca co-doped silica fibre can be useful for high-power fibre lasers. © The Institution of Engineering and Technology 2013.