Photoluminescence of Dy3+ and Sm3+: SiO2–Al2O3–LiF–CaF2 glasses

In this paper, we present the absorption and photoluminescence properties of Dy3+ and Sm3+ (1.0 mol%) ions doped SiO2–Al2O3–LiF–CaF2 glasses. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) profiles of these rare-earth ions doped glasses have been carried out, to confirm their structure and thermal stability. From the DSC thermograms, glass transition temperature (Tg), crystallization temperatures (Tc1 and Tc2) and melting temperature (Tm) have been evaluated. These glasses have shown strong emission and absorption bands in ultraviolet and visible region. For Dy3+ doped glass, a bright fluorescent blue emission at 482 nm (4F9/2→6H15/2) and yellow emission at 574 nm (4F9/2→6H13/2) have been observed, apart from (4I13/2, 4F7/2)→6H13/2 (454 nm) and 4F9/2→6H11/2 (662 nm) two comparative weak emission transitions with 348 nm (6H15/2→4M15/2+6P7/2) excitation wavelength. With regard to Sm3+: glass, emission bands of 4G5/2→6H5/2 (563 nm), 4G5/2→6H7/2 (599 nm) and 4G5/2→6H9/2 (647 nm) have been recorded with an excitation at 6H5/2→4F7/2 (401 nm). Of them, 4G5/2→6H7/2 (599 nm) has shown a bright orange emission. Upon exposure to UV radiation, Dy3+ and Sm3+ glasses have shown bright blue–yellow and orange colors, respectively, from their surfaces.