Effect of the Addition of Pb(3)O(4) and TiO(2) on the Optical Properties of Er(3+)/Yb(3+):TeO(2)–WO(3) Glasses

[Image: see text] Heavy metal oxide tungstate-based tellurite glasses TeO(2)–WO(3) (TW) containing Er(3+)/Yb(3+) ions have been prepared by the melting and quenching method. The optical absorption and upconversion (UC) emission studies for the doped/codoped glasses have been performed. The effect of the addition of Pb(3)O(4) and TiO(2) to the Er(3+)/Yb(3+):TW glass on its physical properties, optical absorption, and UC emission spectra under 980 nm/808 nm excitations has been studied. A significant enhancement in the UC emission intensity lying in the green and red region has been observed on introducing Pb(3)O(4) and TiO(2) into the Er(3+)/Yb(3+):TW glass. The improvement in the UC emission intensity and full width at half maximum of the bands have been explained on the basis of energy transfer, local field correction factor, and Urbach energy. The non-color tunability in the color emitted from the prepared Er(3+)/Yb(3+):TWPTi glass upon near-infrared (NIR) excitation at different pump power has been reported. Also, the color-correlated temperature and color purity have been measured under both NIR excitations.