50GeSe2-25In2Se3-25CsI glass doped with Tm3+, Tm3+/Ho3+ and Tm3+/Er3+ for amplifiers working at 1.22 μm

Se-based chalcohalide glass of 50GeSe2-25In2Se3-25CsI was prepared. The thermal and optical characterizations revealed that this host was thermally and optically superior for practical applications. Strong emission centered at 1.22 μm was observed in all Tm3+ single-doped, Tm3+/Ho3+ and Tm3+/Er3+ co-doped samples with an excitation of 808 nm wavelength. The emission was attributed to the Tm3+: 3H5→3H6 transition. The co-doping of Ho3+ or Er3+ largely broadened the width and slightly strengthened the intensity of the 1.22 μm emission. The possible energy transfer processes and luminescence kinetics were figured. In addition, its potential application as the host material for novel optical amplifiers was discussed.