Abstract: 60P₂O₅·6Al₂O₃·(33-x)BaO·xBaF₂·1Yb₂O₃(x=0,3,6,9) and 60P₂O₅·6Al₂O₃·27BaO·6MF₂·1Yb₂O₃(M=Mg, Ca, Zn, Sr, Ba) glasses were prepared. The influence of bivalent fluoride MF₂(M=Mg,
Ca, Zn, Sr, Ba) on physical properties (such as refractive index, infrared spectra, density etc.) and thermal stability of phosphate glasses were investigated,
as well as influence on glass structure through analysis of their UV and IR spectra. In addition, the absorption and fluorescent properties of Yb³⁺ ions were measured.
The optical parameters (such as integrated absorption cross section and stimulated emission cross section, radiative lifetime etc.) of Yb³⁺ ions in samples were
calculated. The effect of bivalent fluoride MF₂(M=Mg, Ca, Zn, Sr, Ba) on the integrated absorption cross section and stimulated emission cross section of ytterbium
phosphate glasses were discussed. The results obtained show that [PO₄] network structure does not change significantly when bivalent fluorides are introduced as glass modifiers
into phosphate glasses, while emission cross section, spontaneous emission probabilities and TWHM(Fluorescence wavelength at half maximum) of ytterbium phosphate glasses are increased.

Key words: ytterbium laser glass, fluoride, phosphate glasses, spectroscopy