研究了Yb3+/Er3+共掺锗碲酸盐玻璃在980nmLD抽运下的上转换发光光谱，发现随着碱金属离子半径的增大，上转换发光强度明显增强。基质玻璃的Raman光谱显示：玻璃的最大声子能量并不随碱金属氧化物之间的取代而发生变化，表明最大声子能量并不是锗碲玻璃上转换发光强度增大的原因。从玻璃无辐射跃迁的角度分析表明：最大能量声子密度的降低是影响Yb3+/Er3+共掺锗碲玻璃上转换发光强度增大的主要原因。

Upconversion fluorescence properties of a new Er3þ/Yb3þ-codoped lead oxyfluorosilicate glass under 975 nm excitation areinvestigated. The blue, intense green and red emissions centered at 408, 529, 545, and 667nm, corresponding to the 2H9/2→4I15/2, 2H11/2→4I15/2, 4S3/2→4I15/2, and 4F9/2→4I15/2 transitions of Er3+, respectively, were simultaneously observed at room temperature. The important role of Yb2O3 in upconversion intensity is observed, and the influence of Yb2O3 and PbF2 on blue, green and red emissions is compared and discussed. The dependence of upconversion intensities on excitation power and possible upconversion mechanisms are evaluated.

Upconversion luminescence characteristics of a multi-rare-earth-doped 0.05K2O-0.1ZnO-0.1BaO-0.2PbO-0.2GeO2-0.35TeO2 glass have been investigated under 976nm excitation for potential use in full colour displays.Two luminescence ions, Er3+ and Tm3+, were used as blue, green and red emitters to control the colour of the emitted light. Sensitizer ions, Yb3+, were used to increase the upconversion emission intensity. With the substitution of Er3+ for Tm3+, the intensities of the blue, green and 657nm upconversion emissions simultaneously increase.

The thermal stability and spectroscopic properties of Er3+-doped Na2O-GeO2-PbO glasses were investigated experimentally. The thermal analysis results show that the thermal stability of the investigated glasses is improved with replacing GeO2 by PbO. Subsequently, Judd-Ofelt (J-O) approach was applied to the room temperature absorption of Er3+ (4f 11) transitions to determine J-O intensity parameters. The reduced values of Ω2 with the substitution of PbO for GeO2 indicate the decrease of covalency of Er O bonding. The stimulated emission cross section of the 4-13-2→4I15-2 transition increases as a consequence of the increase of refractive index of glass hosts and the narrowing of fluorescence bandwidth with the increase of PbO. The abnormal large emission cross section and large bandwidth in the Na2O-0.8GeO2-0.1PbO glass arises from the change of germanium coordination with oxygen.

In this article, we present a study of a new glass system: lead-germanium-tellurite glasses in the form of 0.05K2O-0.1ZnO-0.1BaO-0.2PbO-xGeO2-(0.55-x) TeO2 with x 0.1, 0.2, 0.3, 0.4, 0.5, and 0.55. Differential temperature analysis of this glass system shows that increasing GeO2 content raises the glass transition temperature (Tg) and suppresses the crystallization tendency in a large temperature range from Tg to the glass melting temperature. The maximum vibrational frequency is intermediate between germanate and fluoride glasses, in the range of 750cm-1 to 820cm-1. Subsequently, Optical absorption, photoluminescence, and upconversion fluorescence were measured for Yb3+, Er3+ co-doped lead-tellurium-germanate glasses. It was found that the full width at half-maximum of the luorescence spectrum at 1534nm decreases and the measured radiative lifetime increases with the replacement of TeO2 by GeO2. Excitation at 976nm into the glass system leads to an intense green emission and a relatively weak red emission. With the addition of GeO2, the increase of red fluorescence and the decrease of green emission in intensity are due to the increase of nonradiative transition rates between the 4S3-2 and 4F9-2 states of Er3+ions. The quadratic dependence of the green and red emissions on excitation power indicates that two-photon absorption process occurs in this glass system excited at 976nm.