Effect of alkali metal oxides R2O (R=Na, K) on 1.53 μm luminescence of Er3+-doped Ga2O3-GeO2 glasses for optical amplification

This paper reported the thermal stability and spectroscopic properties of Ga2O3-GeO2-Na2O-K2O (GGNK) glasses doped with Er3+. The GGNK glasses were characterized by differential scanning calorimetry (DSC), Raman spectra, absorption and infrared-visible fluorescence spectra. Measured DSC result showed that these glasses possessed an excellent stability (ΔT=188.6 °C). The relationship between glass composition and Judd-Ofelt intensity parameters and other optical properties of Er3+, such as the absorption and stimulated emission cross-sections, were clarified. Meanwhile an intense broadband 1.53-μm emission with a full width at half- maximum of 51 nm and peak emission cross-section of 9.32×10−21 cm2 of Er3+-doped GGNK glass was obtained upon 980 nm diode-laser excitation. Effects of K2O replacing Na2O on the thermal stability and spectroscopic properties were investigated. It was found that the incorporation of K2O into Er3+-doped Ga2O3-GeO2-Na2O glass could effectively improve the 1.53 μm emission luminescence. The results showed that GGNK glass might be more attractive host material for their application in C-band optical fiber amplifiers.