Effects of alkali ions on thermal stability and spectroscopic properties of Er3+-doped gallogermanate glasses

Since information transportation capacity of optical communication network increases rapidly, new optical materials are always demanded with gain bandwidth desirably much broader than traditional erbium-doped silica fiber amplifier (EDFA). We show here in this paper the erbium-doped gallogermanate glasses with a full-width at half-maximum (FWHM) more than 50 nm. Incorporation of alkali ions such as Li+, Na+, K+ into the system can on the one hand improve the thermal stability of the glasses, and on the other hand enhance the emission at 1.5 μm due to the 4I13/2→4I15/2 transition of Er3+ and suppress the upconversion process at the same time. This particularly works best for the case of K+ inclusion. This work might give a general idea on controlling the Er3+ luminescence by simply adjusting the glass component and find a potential laser glass applicable to developing new broadband fiber amplifier. -- Research highlights: → We report on spectroscopic properties of Er3+-doped Ga2O3-GeO2-R2O (GGR, R=Li, Na and K) glasses for 1.53 μm fiber amplifier. Effects of alkali metal ions on the thermal stability and spectroscopic properties of Er3+-doped GGR glasses have been investigated. → Incorporation of alkali ions such as Li+, Na+, K+ into the system can on the one hand improve the thermal stability of the glasses, and on the other hand enhance the emission at 1.5 μm due to the 4I13/2→4I15/2 transition of Er3+ and suppress the upconversion process at the same time. This particularly works best for the case of K+ inclusion. This work might give a general idea on controlling the Er3+ luminescence by simply adjusting the glass component and find a potential laser glass applicable to developing new broadband fiber amplifier.