Mid-infrared (3-5 μm) emission from rare earth doped KPb 2 Br 5

Solid-state lasers operating in the mid-infrared (MIR) wavelength region (3-5 μm) are of significant current interest for laser remote sensing of chemical and biological agents as well as for military countermeasures. The development of MIR solid-state lasers based on oxide and fluoride laser hosts is limited by non-radiative decay through multi-phonon relaxations. Rare earth doped crystals with low maximum phonon energies can exhibit efficient MIR emission at room temperature. In this paper, we present results of the material synthesis and optical properties of rare earth (Pr, Nd, Dy, Er) doped KPb 2 Br 5 , which has a maximum phonon energy of only ~140 cm -1 .