Spectroscopic properties and energy transfer in Ga2O3–Bi2O3–PbO–GeO2 glasses doped with Er3+ and Tm3+

This paper reports on the spectroscopic properties and energy transfer of Er3+ and Tm3+ codoped Ga2O3–Bi2O3–PbO–GeO2 (GBPG) glass upon excitation of 808 nm laser diode. The measured emission peak from the 4I13/2→4I15/2 transition of Er3+ located at 1530 nm with a full-width at half-maximum (FWHM) of ∼60 nm. The calculated peak stimulated emission cross-section and the measured lifetime of this transition are ∼12.2×10−21 cm2 and ∼2.97 ms, respectively. It is noted that FWHM of the 1.53-μm emission of Er3+ has been significantly improved from 60 to 170 nm with increase in Tm3+ concentration. Furthermore, the incorporation of Tm3+ into Er3+-doped systems has also resulted in lower green-upconversion emission intensity. The possible mechanism and related discussions on this phenomenon have been presented. The results show that Er3+/Tm3+-codoped GBPG glass might be a promising candidate for the development of broadband amplifiers materials.