Spectral properties and anti-Stokes luminescence of TeO2–BaF2:Ho3+, Ho3+/Yb3+ ceramics and glass excited by 1.9-μm radiation of a Tm:LiYF4 laser

Abstract

We demonstrate the up-conversion of Tm:LiYF₄ infrared (IR) laser radiation with 1908-nm wavelength into visible light with a spectral maximum at 650 nm by ceramics with a composition of (100 − x)TeO₂−xBaF₂ − 1 wt % HoF₃−yYbF₃, where x = 20, 30, or 40 mol % and y = 0 or 0.5 wt %. The samples of 60TeO₂−40BaF₂ − 1 wt % HoF₃ − 0.5 wt % YbF₃ exhibited anti-Stokes luminescence at a threshold radiation power density of 1.0−1.5 W cm⁻².