Growth and characterization of nonhygroscopic KPb₂Br₅:CeBr₃ and TlPb2Br₅:DyBr₃ midinfrared lasing media

Halide-based crystals have been an active area of research, especially in the development of mid-infrared solid-state lasers. Of those, crystals containing bromine show promise due to their higher atomic mass, which offer a solution to multi-phonon relaxation processes affecting mid-infrared energy transitions. In this work, we present the single crystal growth of rare-earth doped KPb₂Br₅:CeBr₃ and TlPb₂Br₅:DyBr₃. FTIR and UV-Vis transmission measurements are presented, and Raman spectra analysis show a maximum phonon energy at 136𝑐𝑚⁻¹ for both crystals. Differential Scanning Calorimetry measurements are shown, alongside with approximate melting points. The results can show how future crystal compositions may be further engineered to further improve crystal quality.