Mid-infrared luminescence of Dy³⁺-doped Ga₂S₃-Sb₂S₃-CsI chalcohalide glasses

The mid-infrared (MIR) luminescent properties of Dy³⁺ ions in a new chalcohalide glass host, Ga₂S₃-Sb₂S₃-CsI, are investigated; and the suitability of the doped glass for MIR fiber lasers is evaluated. The Dy³⁺-doped chalcohalide glasses exhibit good thermal stability and intense MIR emissions around 2.96 μ and 4.41 μm. These emissions show quantum efficiencies (η) as high as ~60%, and have relatively large stimulated emission cross sections (σ_em). The low phonon energy (~307 cm^-1) of the host glass accounts for the intense MIR emissions, as well as the high η. These favorable thermal and emission properties make the Dy³⁺-doped Ga₂S₃-Sb₂S₃-CsI glasses promising materials for MIR fiber amplifiers or lasers.