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.