This paper provides an overview of mid-infrared lasers based on rare-earth-ion-doped selenide glasses. Laser action was demonstrated at the transitions between the first excited and the ground levels of Ce3+, Pr3+, Nd3+ and Tb3+ ions. The highest output parameters for bulk glass lasers (over 40 mJ of output energy) and wavelength tuning in the range of 4.6–5.6 microns were obtained with Ce3+-doped glass. The highest output parameters for fiber lasers (150 mW at 5.1–5.3 μm under continuous pumping) were demonstrated with Tb3+ ions. The longest lasing wavelengths for any glass laser and tunability within the 5.56–6.01 µm spectral band were shown with Nd3+ ions in a Tb3+-Nd3+ co-doped system.
