Comparative investigation of up-conversion luminescence in Tm3+-doped oxide-chloride germanate and tellurite glasses

Tm3+-doped oxide-chloride germanate and tellurite glasses have been synthesized by conventional melting method. Intense up-conversion luminescence emissions were simultaneously observed at room temperature in these glasses. The possible up-conversion mechanisms are discussed and estimated. However, in these Tm3+-doped glasses, tellurite glass showed weaker up-conversion emissions than germanate glass, which is inconsistent with the prediction from the difference of maximum phonon energy between tellurite and germanate glasses. In this paper, Raman spectroscopy was employed to investigate the origin of the difference in up-conversion luminescence in the two glasses. Our results confirm that, besides the maximum phonon energy, the phonon density of host glasses is also an important factor in determining the up-conversion efficiency. (c) 2005 Elsevier Ltd. All rights reserved.

Up-conversion luminescence analysis in ytterbium-sensitized erbium-doped oxide-halide tellurite and germanate-niobic-lead glasses

Ytterbium-sensitized erbium-doped oxide-halide tellurite and germanate-niobic-lead glasses have been synthesized by conventional melting method. Intense green and red emissions centered at 525, 546 and 657 nm, corresponding to the transitions H-2(11/2) -> I-4(15/2), S-4(3/2) -> I-4(15/2) and F-4(9/2) -> I-4(15/2), respectively, were simultaneously observed at room temperature in these glasses. The quadratic dependence of the 525, 546 and 657 nm emissions on excitation power indicates that a two-photon absorption process occurs. Tellurite glass showed a weaker up-conversion emission than germanate-niobic-lead glass, which is inconsistent with the prediction from the difference of maximum phonon energy between tellurite and germanate-mobic-lead glasses. In this paper, Raman spectroscopy was employed to investigate the origin of the difference in up-conversion luminescence in the two glasses. Compared with phonon side-band spectroscopy, Raman spectroscopy extracts more information including both phonon energy and phonon density. Our results reveal that the phonon density and the maximum phonon energy of host glasses are both important factors in determining the up-conversion efficiency. (c) 2005 Elsevier B.V. All rights reserved.

Intense upconversion luminescence in ytterbium-sensitized thullum-doped oxychloride germanate glass

Structural and upconversion fluorescence properties in ytterbium-sensitized thulium-doped oxychloride germanate glass have been studied. The structure of oxychloride germanate glass was investigated by peak-deconvolution of Raman spectrum, and the structural information was obtained from the peak wavenumbers. The Raman spectrum investigation indicates that PbCl2 plays an important role in the formation of glass network, and has an important influence on the upconversion luminescence. Intense blue and weak red emissions centered at 477 and 650 nm, corresponding to the transitions (1)G(4) ->(3) H-6 and (1)G ->H-3(4), respectively, were observed at room temperature. The possible upconversion mechanisms are discussed and estimated. Intense upconversion luminescence indicates that oxychloride germanate glass can be used as potential host material for upconversion lasers. (c) 2004 Elsevier B.V. All rights reserved.

BaF2替代BaO对钡镓锗酸盐玻璃光学性质的影响

在摩尔分数组成x(BaO),r(Ga2O),r(GeO2)为0．20，0．15,0．65的玻璃中，分别以摩尔分数0．05，0．10．0．15和0．20的BaF2替代BaO,研究了氟化物对玻璃折射率和光吸收性质的影响。结果表明，在玻璃中加入氟化物．玻璃折射率和色散降低，玻璃的紫外吸收边向短波侧迁移，而红外吸收边无明显变化。不含氟化物的氧化物玻璃中含有大量的OH基．这些OH基在2．24μm、2．97μm和4．23μm附近引起光吸收．在含氟化物的玻璃中，2．24μm的吸收峰消失，而2．97μm和4．23μm附近

透红外大尺寸氧氟化物玻璃研究

锗酸盐和氟铝酸盐透红外玻璃材料作为窗口或头罩材料具有广泛的应用前景。结合锗酸盐玻璃含有少量水的问题，在成分中引入氟化物，实验表明：随氟化物含量增加．玻璃中羟基含量逐渐降低。同时通过对熔制温度的调整，获得了不合羟基的红外玻璃。针对氟铝酸盐玻璃在冷却过程中易析晶的问题，在氟化物组分中加入少量重金属氧化物TeO2，得到析晶性能好的氧氟铝酸盐玻璃。同时给出了两类红外材料的一些物理、化学性质。