Optical properties of Sm 3+ ions in lithium borate and lithium fluoroborate glasses

Abstract

Optical absorption, excitation, emission spectra and lifetimes are presented for Sm 3+ ions in lithium borate and lithium fluoroborate glasses. Compositional dependence of Judd–Ofelt parameters has been evaluated and these parameters are used to predict radiative lifetimes ( τ R) and branching ratios ( β R) for some excited 4G(4) 7/2, 4G(4) 5/2, 6F 11/2, 6F 9/2, 6F 1/2, 6H 13/2, 6H 11/2 and 6H 9/2 levels. The radiative properties have also been predicted for these excited levels of Sm 3+:borate, oxide, phosphate, fluoride and fluorophosphate glasses and Sm 3+:Y 3Al 5O 12 crystal. The values of electric ( A ed) and magnetic ( A md) dipole transition probabilities, τ R and β Rare presented for the above excited levels. The Judd–Ofelt intensity parameters have been used to predict oscillator strengths which are found to be useful to assign the closely spaced multiplets. The predicted values of τ R and β R are compared with the experimental values for 4G(4) 5/2 level to its lower levels. The stimulated emission cross-sections, σ( λ p), were also evaluated for 4G(4) 5/2→ 6H J transitions. The dependence of the optical properties due to compositional changes of the glasses are discussed and compared with similar results.