Frequency upconversion in Er3+ doped alkali bismuth gallate glasses

Upconversion of infrared light to visible light in rare earth ions doped glasses and crystals have been extensively investigated due to their applications in the areas of color display, optical data storage, optoelectronics, medical diagnostics and undersea optical communications. Upconversion is difficult to generate in conventional oxide glasses due to the high phonon energies corresponding to the high vibration energies of the oxide glass networks. However, oxide glasses have high chemical stability and ease of fabrication. Upconversion fluorescence has been reported in Er³⁺ doped TeO₂-Na₂O and TeO₂-PbO glasses. However, the upconversion efficiency is poor due to the high phonon energies inherent in tellurite glasses (700 - 800 cm^-1. The properties of KBG glasses were characterized, and comparison was made with tellurite K₂O-ZnO-TeO₂ (KZT) glasses. The upconversion fluorescence of Er³⁺ in alkali bismuth gallate (KBG) glasses was investigated, and optical waveguides were demonstrated in these oxide glasses using the ion-exchange process