Tm3+ doped Bi2O3–GeO2–Na2O glasses for 1.8 μm fluorescence

Abstract 53.3BiO 1.5 –33.3GeO 2 –13.4NaO 0.5 (cation%) glasses with various Tm 3+ concentration were prepared by melt-quenching method. These glasses show high density, high refractive index, low phonon energy and good stability against crystallization. Absorption spectra of Tm 3+ -doped bismuthate glass were measured to obtain the radiative lifetimes by Judd-Ofelt theory. The absorption (4.5 × 10 −21  cm 2 ) and emission (6.7 × 10 −21  cm 2 ) cross-sections were calculated by Beer–Lambert and McCumber theory. The results show that the Tm 3+ ( 3 F 4  →  3 H 6 ) in these glasses have high spontaneous radiative transition probabilities and large stimulated emission cross-section. Then the fluorescence emission spectra were measured under 808 nm excitation and the maximum emission intensity at 1.8 μm is obtained at 0.9 mol% Tm 2 O 3 in the glasses.