Ce³⁺-Doped Selenide-Glass Lasers Tunable in the $\mathbf{4.5}-\mathbf{5.6}\ \boldsymbol{\mu} \mathbf{m}$ Range

Recent progress in the fabrication of high-purity chalcogenide glasses [1] opened new possibilities for the development of novel mid-infrared rare-earth doped glass lasers (e.g., based on Pr ³⁺ , Tb ³⁺ , and Ce ³⁺ ) emitting in the spectral range of $4-6\ \ \mu \mathrm{m}$ . The best results up to now have been obtained in high-purity Ce ³⁺ -doped $\text{Ge}_{20}\text{Sb}_{10}\text{Ga}_{5}\text{Se}_{65}$ glass rods [2]–[5].