Photoluminescence properties of Sm3+-doped SFB glasses for efficient visible lasers

Abstract The photoluminescence properties of different concentrations of Sm 3+ ions doped sodium fluoroborate (SFB) glasses of composition Na 2 O–LaF 3 –CaF 2 –AlF 3 –B 2 O 3 –SmF 3 have been investigated. The energy level analysis is carried out using free-ion Hamiltonian model. The Judd–Ofelt intensity parameters are used to evaluate the laser characteristic parameters such as spontaneous transition probability, radiative lifetime and fluorescence branching ratio for 4 G 5/2  →  6 H J (J = 5/2, 7/2, 9/2 and 11/2) emission transitions of Sm 3+ ion. The principal photoluminescence transitions of interest are identified by recording the emission spectra for different Sm 3+ ion concentrations and measuring their emission cross-sections, integrated absorption cross-sections and optical gain parameters. The decay profiles from the 4 G 7/2 excited manifold state to its lower lying energy levels have been recorded by monitoring the excitation and emission wavelengths at 402 and 600 nm, respectively. The dependence of effective fluorescence lifetime on the Sm 3+ concentration is also discussed.