Praseodymium-doped alkali bismuth gallate glasses

We propose and demonstrate alkali bismuth gallate glasses as suitable hosts for the rare earth praseodymium (Pr3+) Operating at 1.3-mu m wavelength. T he structure of the glasses was investigated by Raman spectroscopy. The opt ical absorption and the photoluminescence properties of Pr3+ in these glass es were characterized. The Raman spectrum shows two strong peaks, at 134 an d 381 cm(-1), and a weak peak at 660 cm(-1) The results indicate that bismu th (Bi3+) and gallium (Ga3+) cations do take part in the formation of the g lass network. The emission from the pr(3+): (1)G(4) --> H-3(5) transition i s at 1.34-mu m wavelength, and the spectral bandwidth is 120 nm, which is w ider than those of fluoride and chalcogenide glasses. The lifetime of the ( 1)G(4) level is similar to 78 mu s, and the quantum efficiency is similar t o 17.4%, which is higher than that in fluoride glasses. (C) 2000 Optical So ciety of America.