Spectral kinetic study of four-component BaF2–ZnF2–CdF2-YbF3 fluoride ceramics by selective laser excitation

Abstract New type of optical material, BaF2:ZnF2:CdF2:YbF3 (1.1 at %) ceramics, contains two phases with different chemical compositions and different crystal structures. BaF2:ZnF2:CdF2:YbF3 (1.1 at %) ceramics is translucent in visible and near-IR spectrum ranges, and it is transparent in mid-IR and terahertz ranges. The spectral-kinetic properties of Yb3+ optical centers in fluoride ceramics are studied by selective laser excitation. The qualitative spectral characteristics (homogeneous and inhomogeneous broadening, Stark splitting, and lifetimes) of Yb3+ optical centers are determined, and two phases with containing YbF3 as an impurity are revealed in this matrix. Two types of clustered Yb3+ optical centers with slow and short fluorescence decay are found, each in the different fluoride phase. The lifetimes of these Yb3+ centers in the first and second phases differ approximately by a factor of four (τ(77К) = 0.34/1.2 ms).