The near- and mid-infrared emission properties of Tm 3+-doped GeGaS–CsI chalcogenide glasses

Abstract

Serials of chalcogenide glasses based on composition of 72GeS 2–18Ga 2S 3–10CsI (in mol%) and doped with high Tm 3+ content (up to 10,000 ppm) were prepared, and their luminescence properties were investigated under excitation with 800 nm laser. The influences of doping concentration on Judd–Ofelt intensity parameter Ω i , spontaneous transition probability A, fluorescence branching ratio β, and radiative lifetime τ rad of Tm 3+ in the samples were studied. Four infrared emission bands observed were centered at 1.48, 1.8, 2.3, and 3.8 μm, corresponding to optical transitions 3H 4 → 3F 4, 3F 4 → 3H 6, 3 H 4 → 3 H 5 and 3H 5 → 3F 4, respectively. For 1.0 wt.% Tm 3+: doped sample, no concentration quenching was observed and its emission cross-sections at 2.3 and 3.8 μm calculated by using Füchtbauer–Ladenburg equation were 6.85 × 10 − 21 and 7.66 × 10 − 21 cm − 2, respectively.