Enhanced and modulated-2.9 μm mid-infrared emission of Ho3+/Pr3+: LiYF4 single crystal by co-doping non active Lu3+ ions

A hitherto undeveloped Pr3+/Ho3+: LiYF4 single crystal by introducing non-active Lu3+ ions was synthesized by a reformative Bridgman technique. The crystalline phases and optical properties of the crystals were characterized using various methods, including absorption spectra, X-ray diffraction (XRD), Rietveld refinement, emission spectra, and lifetimes. The band gaps of Ho3+/Pr3+: LiYF4 (Ho3+/Pr3+: LYF) and Ho3+/Pr3+/Lu3+: LiYF4 (Ho3+/ Pr3+: LLYF) single crystal were calculated by density functional theory, the value is-7.902 eV and-7.692 eV, respectively. The-2.9 mu m emission intensity significantly increased about two times when Lu3+ (3.0 mol%) was added to 0.1Pr3+/0.5Ho3+: LiYF4single crystal due to the disruption of [Ho3+-Ho3+] quenching clusters formed by Ho3+ ions. The maximum emission cross section of 0.1Pr3+/0.5Ho3/3.0Lu3+: LiYF4 single crystal was-22.7 x 10-21 cm2. The doping of Lu3+ ions reduced significantly the lifetime of 5I7 energy level and mitigates effectively the self-termination phenomenon. Thus, the incorporation of Pr3+/Ho3+/Lu3+ into LiYF4 single crystal represented a promising choice for a laser gain medium operating at-2.9 mu m, as well as for other optoelectronic devices.