A new study on bismuth doped oxide glasses

Spectroscopic properties of bismuth doped borate, silicate and phosphate glasses have been reinvestigated in this work. It shows the typical decay time of Bi3+ is around 500ns rather than 2.7-to-3.9 mu s reported by Parke and Webb at room temperature. Introduction of higher content either alkali or alkali earth into borate glasses favors the Bi3+ emission. As the contents increase excitation peak shifts regularly red while emission peak shows reverse trend. This, as revealed by Huang-Rhys factor, is due to the weakening of coupling between bismuth and glass host, and it can be interpreted within the frame of configurational coordinate diagrams. Differently, as bismuth concentration increases, both the excitation and emission shift red. The unknown origin of red emission from bismuth doped calcium or magnesium phosphate glass has been identified as Bi2+ species on the basis of excitation spectrum and emission lifetime particularly after comparing with Bi2+ doped materials. No near infrared (NIR) emission can be detected in these glasses within instrument limit. (C) 2012 Optical Society of America