Optical characterization of Tm 3+ doped Bi2O3-GeO2-Ga2O3 glasses in absence and presence of BaF2

Abstract

In this paper, Two new Bi2O3-GeO2-Ga2O3 glasses (one presence of BaF 2) doped with 1mol% Tm 2 O 3 were prepared by melt-quenching technique. Differential thermal analysis (DTA), the absorption, Raman, IR spectra and fluorescence spectra were measured. The Judd-Ofelt intensity parameters, emission cross section, absorption cross section, and gain coefficient of Tm 3+ ions were comparatively investigated. After the BaF 2 introduced, the glass showed a better thermal stability, lower phonon energy and weaker OH-absorption coefficient, meanwhile, a larger ∼1.8 μm emission cross section σ em (7.56 × 10-21 cm2) and a longer fluorescence lifetime I., mea (2.25 ms) corresponding to the Tm 3+: 4 F3 →' 3 H6 transition were obtained, which is due to the addition of fluoride in glass could reduce the quenching rate of hydroxyls and raise the cross-relaxation (3H6 + 3 H 4 →' 3 F4 + 3 F4) rate. Our results suggest that the Tm 3+ doped Bi2O3-GeO2-Ga2O3 glass with BaF 2 might be potential to the application in efficient ∼1.8 μm lasers system.