LUMINESCENCE AND ABSORPTION OF TB3+ IN MO.AL2O3.B2O3.TB2O3 GLASSES

Quantum yields of the green Tb luminescence for 254 nm excitation of glass compositions in the system MO multiplied by (times) Al//2O//3 multiplied by (times) B//2O//3 multiplied by (times) Tb//2O//3 (M equals Mg, Ca, Sr, Ba and Zn) were studied in relation to absorption and excitation spectra. Yields as high as 80% were observed. The Tb 4f-5d absorption maximum ranges from 218 to 232 nm, always at a longer wavelength than the glass matrix absorption. The yield strongly depends on the spectral position of the 4f-5d absorption, due to competing impurity absorption at 254 nm.