Photoluminescence properties of Sm3+ in LBTAF glasses

Room temperature visible and near infrared optical absorption and emission spectra of Sm3+-doped lead borate titanate aluminum fluoride (LBTAF) glasses with molar composition (50−x) PbO−30H3BO3−10TiO2−10AlF3−xSm2O3 (x=0.1, 0.5, 1.0 and 2.0) have been analyzed. Energy parameters for the 4f5 electronic configuration of Sm3+: LBTAF glasses have been evaluated using free-ion Hamiltonian model. The experimental oscillator strengths of absorption bands have been used to determine the J–O parameters. Fluorescence spectra were recorded by exciting the samples with 402 nm. Using the J–O parameters and luminescence data, the radiative transition probabilities (AR), branching ratios (βR) and stimulated emission cross-sections (σe) were obtained. The decay curves of 4G5/2→6H7/2 transition exhibit single exponential for lower concentration (0.1 mol%) and non-exponential for higher concentrations. This concentration quenching has been attributed to the energy transfer through cross-relaxation between Sm3+ ions. From the values of the radiative parameters, it is concluded that 1.0 mol% Sm3+-doped LBTAF glass may be used for laser active medium with emission wavelength at 600 nm.