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. The structure of the glasses was investigated by Raman spectroscopy. The optical absorption and the photoluminescence properties of Pr3+ in these glasses were characterized. The Raman spectrum shows two strong peaks, at 134 and 381 cm(-1), and a weak peak at 660 cm(-1) The results indicate that bismuth (Bi3+) and gallium (Ga3+) cations do take part in the formation of the glass network. The emission from the pr(3+): (1)G(4) --> H-3(5) transition is at 1.34-mu m wavelength, and the spectral bandwidth is 120 nm, which is wider 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 to 17.4%, which is higher than that in fluoride glasses. (C) 2000 Optical Society of America.