Luminescence study of rare-earth (RE)-doped low-energy phonon RbPb2Cl5 crystals for mid-infrared (IR) lasers emitting above 4.5 μm wavelength

Ternary alkali lead halides doped by rare-earth ions are considered to be suitable materials for solid-state lasers operating in the broad spectral range from ultraviolet to mid-infrared (IR) wavelengths. This contribution is focused mainly on the luminescence study of the low-phonon energy rubidium lead chloride RbPb2Cl5 (RPC) materials doped with a low concentration of trivalent neodymium (5 mol%), praseodymium (5 mol%), and dysprosium (0.1 mol%) ions. Broad emission bands with maxima around 4.70 m, 5.25 m, and 5.15 m were observed in Pr:RPC, Nd:RPC, and Dy:RPC samples, respectively, which makes these materials promising for future mid-IR laser development, especially in terms of their broad tunability and/or ultrashort pulse generation.