Compositional optimization of bismuth-doped yttria–alumina–silica glass

We fabricated three series of glasses in which the Y2O3, Bi2O3 and Al2O3 contents of Bi-doped Y2O3:Al2O3:SiO2 glass were varied. We optimized the content of each component based on quantum efficiency (QE) and other optical properties. The strength of the Bi absorption bands decreased with increasing Y2O3 content. The optimized composition was: 63.5SiO2:22.5Al2O3:13Y2O3:1Bi2O3. With 808 nm excitation this glass had a QE, lifetime, emission width and peak of 20%, 375 μs, 293 and 1240 nm, respectively. The Bi absorption strength had a quadratic dependence on Bi2O3 content. This indicates that the optically active Bi center is Bi2 dimers.