Optical properties of bismuth in germanate, borax and phosphate glasses

Absorption, emission, excitation spectra and quantum efficiencies of luminescence of bismuth were obtained in germanate, borax and phosphate glasses. Decay times were measured for fluorescence of bismuth in germanate glass at room temperature and liquid air temperature. A non-exponential decay of fluorescence at room temperature is observed. A thermal equilibrium between the ³P₁ and ³P₀ states is discussed. The dependence of fluorescence intensity and decay times on temperature is presented. The amount of covalency between bismuth and glass matrix was calculated from the nephelauxetic effect.