Effect of the odd intensity parameters and optical properties of Tb3+ doped fluoroindate glasses

In the present paper we report on the detailed spectroscopic analysis of the Tb3+-doped fluoroindate glasses with different Tb3+ concentration. Absorption spectra in the spectral range from 320 to 6,000 nm were recorded and analyzed for all samples by applying the standard and modified Judd–Ofelt theory. It is well known that in some cases application of the standard Judd–Ofelt theory results in getting negative values for the Ω2 intensity parameter, which is in obvious contradiction to the definition of the Ωλ (λ = 2, 4, 6) parameters. We demonstrate that it is possible to obtain positive values for all intensity parameters Ωλ by including the odd intensity parameters (λ = 1, 3, 5). Using the standard and modified Judd–Ofelt theory, we obtained the values of the intensity parameters and calculated the oscillator strengths and branching ratios for electric dipole optical transitions in all samples. Comparison with experimental data is discussed.