Tungsten-tellurite glass:: a new candidate medium for Yb3+-doping

Yb3+-doped tungsten-tellurite glasses with compositions of (50-70)TeO2-(30-10)WO3-20Li(2)O, (80-90)TeO2-(10-0)WO3-10Ba(2)O, (65-75)TeO2-(25-15)WO3-10La(2)O(3), (55-65)TeO2-(35-25)WO3-10Bi(2)O(3) and (80-85)TeO2-(10-5) WO3-10Nb(2)O(5) (mol%) have been prepared. Thermal stability and spectroscopic properties of Yb3+-doped ternary tungsten-tellurite glasses have been measured. Yb3+-doped La2O3- and Nb2O5-containing ternary tungsten-tellurite glasses possess the difference between the glass transition temperature (T-g) and the onset crystallization temperature (T-x), Delta T (= T-x - T-g) > 160 degrees C, a flat absorption shoulder located between 940 and 960 nm region with absorption cross-sections > 0.5 x 10(-20) cm(2), secondary emission cross-sections (at similar to 1.02 mu m) > 0.7 x 10(-20) cm(2), and the ratios of secondary-to-primary peak emission cross-sections, sigma(s)/sigma(p) > 70%, respectively. (C) 1999 Elsevier Science B.V. All rights reserved.