| abstract |
A family of alkali-tungsten-tellurite glasses that consist essentially of, as calculated in mole percent, 10-90% TeO 2 , at least 5% WO 3 and at least 0.5% R 2 O where R is Li, Na, K, Cs, Tl and mixtures, that may contain a lanthanide oxide as a dopant, in particular erbium oxide, and that, when so doped, is characterized by a fluorescent emission spectrum having a relatively broad FWHM value. |