Effects of Yb ³⁺ in Er ^3+/Yb ³⁺ Codoped Fluorophosphate Glasses

For the Er³⁺/Yb³⁺ codoped fluorophosphate glasses, Judd--Ofelt theory is used to analyse the influence of YbF₃ as not a sensitizer but an average component on the spectroscopic properties around 1530\,nm emission. The double roles of Yb³⁺, as a sensitizer and as an average component, are discussed. It is found that Yb³⁺ as an average component contributes to the increase of fluorescence lifetime, and Yb³⁺ as a sensitizer has the best sensitization when its concentration is 2.4mol%.