Spectroscopic Investigation of Sm3+ doped phosphate based glasses for reddish-orange emission

Spectroscopic properties of Sm3+ ions in phosphate based glasses (P2O5+K2O+Al2O3+CaF2) were investigated through SEM with EDS, X-ray diffraction (XRD), differential thermal analysis (DTA), Fourier transform infrared (FTIR), Raman, absorption, emission and decay measurements. Judd-Ofelt (JO) intensity parameters were obtained from the absorption spectrum which are inturn used to calculate the emission properties such as radiative transition probabilities (AR), radiative lifetime (τR), branching ratios (βR) and stimulated emission cross-sections (σe(λP)) for the 4G5/2→→6HJ (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 4G5/2 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.