Spectroscopic investigations of Sm3+doped phosphate glasses: Judd-Ofelt analysis

Abstract

Phosphate glasses with chemical compositions of (42– x/2) P2O5-(42– x/2)Na2O-15ZnO–xSm2O3 were synthetized by melt quenching method. We investigated the influence of Sm3+ doping on the optical properties of phosphate glasses. X-Ray Diffraction indicates that the samples have an amorphous structure. DSC measurements show a good thermal stability of phosphate glasses. Using the absorption spectra, Judd-Ofelt analysis was applied to absorption bands of Sm3+ (4f5) to carry out the three phenomenological parameters of Judd-Ofelt (JO). According to the obtained values of Ω2, Ω4 and Ω6, some radiative properties were theoretically determined. Photoluminescence (PL) spectra show three transitions of Sm3+: 4G5/2 → 6H5/2 (600 nm), 4G5/2 → 6H7/2 (564 nm) and 4G5/2 → 6H9/2 (645 nm). The concentration dependency of PL intensity was investigated. The quenching of the PL intensity occurs at the Sm3+ concentration above 1%. The predicted lifetime (τr) calculated by using JO method and the measured lifetime (τmea) determined experimentally for 4G5/2 level, were discussed and compared with those of other works. With the weak spectroscopic quality factors Ω4/Ω6 (0.76), we expect a relatively prominent infrared laser emission.