Effect of neodymium ions on upconversion fluorescence studies of oxyfluorosilicate glasses for optoelectronic devices

Effect of Nd2O3 concentrations on optical properties and upconversion studies were investigated for oxyfluorosilicate glasses with composition of SiO2-Al2O3-Na2CO3-SrF2-CaF2. The Judd-Ofelt (JO) intensity parameters, Ωλ (λ = 2, 4 and 6) as well as radiative properties for the 4F3/2 level of Nd3+ ion have been evaluated from the absorption spectra of 1.0 mol% Nd2O3-doped glass. For all the glass samples, the strong NIR emissions were observed at 891, 1058 and 1330 nm and have been attributed to 4F3/2 → 4I9/2,11/2, 13/2 transitions respectively. The stimulated emission cross-section for the 4F3/2 → 4I11/2 transition is evaluated and found to be 4.24 × 10-20 cm2. From the decay curves, experimental lifetimes (τexp) of the 4F3/2 level have been determined and are found to be 363, 340, 205, 134, 122 and 54 μs for 0.1, 0.5, 1.0, 1.5, 2.0 and 3.0 mol% Nd3+ ions doped glasses, respectively. By exciting the prepared glass samples at 808 nm, the upconversion of infrared light into blue, green, yellow and red emission have also observed. These results indicate that the present glasses could be useful for opto-electric devices and solid state laser applications.