Optical properties of lithium lead borate glass containing copper oxide for color filter and absorption glass

Lithium lead borate glass samples containing copper oxide are prepared using the normal melt-quenching technique. The optical constants are investigated and discussed with the substitution of Pb3O4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {Pb}_{3}\hbox {O}_{4}$$\end{document} for CuO. The UV/VIS/NIR absorption spectra have been recorded at room temperature. The optical energy band gap Eopt\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {E}_{\mathrm{opt}}$$\end{document} and Urbach energy Etail\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {E}_{\mathrm{tail}}$$\end{document} was determined. The increase of Eopt\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {E}_{\mathrm{opt}}$$\end{document} and UV cut off are due to the decrease of nonbridging oxygen concentration with increase of CuO content. The decrease of Etail\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {E}_{\mathrm{tail}}$$\end{document} at higher concentrations is attributed to the copper ion accumulation in the interstitial positions and to the formation of orthoborate groups. Refractive index (measured and calculated), molar refraction and polarizability are correlated with the composition of the glasses. And produce a longpass filters with cutoffs in the range of 190–400 nm.