The study of Sm3+-doped low-phonon-energy chalcohalide glasses

The Sm3+-doped low-phonon-energy (LPE) Ge–Ga–Se–CsI glasses were studied. Upon excitation at 980 nm diode laser, intense 1.25 and 1.49 μm near-infrared fluorescence bands with broad full width at half maximum (FWHM) of 49 and 53 nm were observed, respectively. About 180–300 μs fluorescence lifetimes were obtained for the 1.49 μm emission. The thermal properties and structure of glasses were investigated by differential thermal analysis (DTA) and Raman spectra, respectively. Spectroscopic characteristics of the optical transitions have been calculated by using the Judd–Ofelt theory and evaluated for excited levels.

Research Highlights
► The intense 1.25 and 1.49 μm near-infrared luminescence of Sm3+ ions in low-phonon-energy Ge-Ga-Se-CsI glasses were reported.
► Long fluorescence lifetimes of 180–300 μs were obtained for the 1.49 μm emission.
► The appearance of new low-energy-phonon bands, including with [Ge(Ga)IxSe4-x], [Ge(Ga)I4] and [Ga2I7]- units, mainly result in the measured lifetime increase of 1.49 μm emission.