Physical and spectroscopic studies of Sm³⁺ doped borate based glasses for reddish-orange emission

Spectroscopic properties of Sm³⁺ ions in borate based glasses (H₃BO₃ + CaCO₃ + NaF₂) were investigated through X-ray diffraction (XRD), Fourier transform infrared (FTIR), absorption, emission and decay curve measurements. Judd-Ofelt (JO) intensity parameters were obtained from the absorption spectrum which are in turn used to calculate the emission properties such as radiative transition probabilities (AR), radiative lifetime (R), branching ratios (β_R) and stimulated emission cross-sections (σ_e(λ_P)) for the ⁴G_5/2 → ⁶H_J (J=5/2,7/2,9/2 and 11/2) transitions of Sm³⁺ ions. The effective fluorescence bandwidth (Δλeff) and the experimental branching ratios (βexp) were determined from the emission spectrum. The decay profiles of ⁴G_5/2 level exhibited non-exponential nature with the increase of Sm³⁺ ions concentration. The non-exponential behavior of decay curves has been explained by using the Inokuti - Hirayama (IH) model for S=6, which indicates that the energy transfer mechanism is dipole-dipole between the Sm³⁺ ions. (author)