Investigating the glass structure of Yb3+/Al3+/P5+ doped silica preforms prepared by suspension method

Owing to its capability to produce large volume of glass while preserving a high degree of purity and homogeneity, the suspension method was employed here to synthesize a Yb3+/Al3+/P5+ doped silica preforms. The glass structure was studied by relying on both nuclear magnetic resonance (NMR) and Raman spectroscopies, confirming the formation of Al(PO)4 units. Thence, photoluminescence emission spectra were acquired, assessing the beneficial impact of the phosphorus addition in Yb/Al doped silica glass to curtail the Yb2+ ions content. The results reported here suggest that alumino-phosphosilicate matrix having an equimolar concentration of Al3+/P5+ co-dopants exhibits significantly weaker concentration in Yb2+ ions than equivalent aluminosilicate matrix. This glass composition is thus shown relevant to look further on circumventing the photodarkening phenomenon occurring into fiber laser.