Influence of Y3+ ions on the optical properties of Dy3+-activated LaF3 single crystal

In this exploration, the 2 at% Dy3+ and 3 at% Y3+ codoped LaF3 single crystal was grown by the temperature gradient technique. The influence of non-optically-active Y3+ ions on the luminescence of Dy3+ ions in LaF3 crystals has been explored. Geometry optimization demonstrates that the crystallographic symmetry for Dy3+ ions can be distorted from C2 to lower symmetry C1. Low temperature excitation and emission spectra prove that Dy3+ ions occupy the same kind of spectroscopic site in Dy3+/Y3+ codoped LaF3 crystals. The Judd-Ofelt (J-O) theory analysis and room temperature fluorescence emission spectra have testified that the fluorescence emission intensity of Dy3+ with Y3+ is several times than that without Y3+ in LaF3 at yellow and mid-infrared region. Codoping with non-optically-active Y3+ ions could weaken the concentration quenching effect of Dy3+ and strengthen the luminescence intensity of Dy3+ ions. •The 2 at% Dy3+ and 3 at% Y3+ codoped LaF3 single crystal was grown by the temperature gradient technique.•Low temperature excitation and emission spectra prove that Dy3+ ions occupy the same kind of spectroscopic site in Dy3+/Y3+ codoped LaF3 crystals.•The Judd-Ofelt theory analysis and room temperature fluorescence emission spectra have testified that the fluorescence emission intensity of Dy3+ with Y3+ is several times than that without Y3+ in LaF3 at yellow and mid-infrared region.•The net gain cross-section spectra show that the tunable laser can be obtained at the range of 2930-3200 nm, when the population inversion p is greater than 0.4.