TeO2-ZnO-Na2O-K2O玻璃中Er^3＋离子掺杂浓度对其发光及荧光寿命的影响

测量了不同掺杂浓度下Er^3+离子在碲酸盐玻璃中的吸收光谱、发射光谱和Er^3+离子的荧光寿命，计算了Er^3+离子的发射截面σc，分析了Er^3+离子掺杂浓度对其发光强度和荧光寿命的影响．结果表明，Er^3+离子掺杂浓度较低时，对其荧光强度和荧光寿命没有显著的影响；掺杂浓度高时，出现了浓度猝灭效应，使Er^3+离子荧光光强度降低，荧光寿命下降．实验确定了掺杂浓度最优值，同时对浓度猝灭机制进行了分析．

Frequency up-conversion properties of Er3(+)-doped TeO2-ZnO-PbCl2 oxyhalide tellurite glasses

This paper reports on the successful preparation and a detailed study on the up-conversion properties of Er3+ -doped TeO2-ZnO-PbCl2 oxylialide tellurite glasses. Three intense emissions centered at around 527, 549 and 666 nm have been clearly observed under 977 nm excitation and the involved mechanisms have been explained. The green emissions centered at 527 and 549 nin are due to the H-2(11/2 ->) I-4(15/2) and S-4(3/2) -> I-4(15/2) transitions, and the red up-conversion emission centered at 666 nm is associated with the F-4(9/2) -> I-4(15/2) transitions of Er3+ ions, respectively. The quadratic dependence of fluorescence on excitation laser power confirm that two-photons contribute to up-conversion of the green-red emissions. (c) 2005 Elsevier B.V. All rights reserved.

Thermal analyses, spectral characterization and structural interpretation of Yb3+ doped TeO2-ZnO-ZnCl2 glasses

Bulk-lasses have been prepared in the TeO2-ZnO-ZnCl2 systems. Their characteristic temperatures were determined and analyzed. Raman and FT-IR spectra were used to analyze the effect of ZnCl2 on the structure and spectral properties of tellurite glasses and OH- groups in this glass system. The spectroscopic properties including absorption spectra, emission cross-sections and fluorescence lifetimes of Yb3+ in TeO2-ZnO-ZnCl2 were measured and calculated. It is demonstrated that the progressive replacement less than 20 mol% of TeO2 by ZnCl2 improves the thermal stability, removes the OH- groups, turns TeO4 bipyramidal arrangement into TeO3 (and/or TeO3+1) trigonal pyramids structures and results in the decrease of the symmetry of the structure, which increases the emission cross-sections and lifetimes. But when the content of ZnCl2 up to 30 mol%, the glass system becomes more hygroscopic and introduces more OH- groups, which decrease the emission cross-sections and shorten the lifetimes. The results show that the glass system with (TeO2)-Te-69-(ZnO)-Zn-10-20ZnCl(2)-1Yb(2)O(3) is a desirable component for active laser media for high power generation. (c) 2005 Elsevier B.V. All rights reserved.

The spectroscopic properties of Er3(+)-doped TeO2-Nb2O5 glasses with high mechanical strength performance

(100 - x)TeO2 - xNb(2)O(5) (x=5-20) mobic tellurite glasses doped with 0.5 mol.% Er2O3 were synthesized, and their thermal, mechanical, and spectroscopic properties were measured and compared to the properties of the typical 75TeO(2)-20ZnO-5Na(2)O (TZN) tellurite glass. The refractive index (n(d)), density (p), and glass transition temperature (T-g) of bulk glasses increase with the Nb2O5 content. The Vickers microhardness (H-v) of bulk glass in niobic tellurite glasses also increases with the Nb2O5 content. The values (2.5-3.2 GPa) of H, in the niobic tellurite glasses are 47-88% larger than that (1.7 GPa) in TZN glass. The effect of Nb2O5 content on absorption spectra, the Judd-Ofelt parameters Omega(t) (t = 2, 4, 6), fluorescence spectra and the lifetimes of Er3+ :I-13/2 level were also investigated, and the stimulated emission crosssection was calculated from McCumber theory. With increasing Nb2O5 content in the glass composition, the Omega(t) (t = 2, 4, 6) parameters, fluorescence full width at half maximum (FWHM) Of I-13/2 of Er3+ increase, while the I-4(13/2) lifetimes of Er3+ decreases. Compared with TZN glass, the gain bandwidth properties of Er3+-doped TeO2-Nb2O5 glass is much larger than in tellurite glass based TeO2-ZnO-Na2O system, bismush-based glass, germanate, and silicate glasses, which indicates that TeO2-Nb2O5 glasses are better choice as a practical available host material for broadband Er3+-doped amplifier. (c) 2005 Elsevier B.V. All rights reserved.

Spectroscopic properties of Er3+ doped TeO2-BaO (Li2O, Na2O)-La2O3 glasses for 1.5-mu m optical amplifiers

This paper reports on the optical spectroscopic properties and thermal stability of Er3+-doped TeO2-BaO (Li2O,NaO)-La2O3 glasses for developing 1.5-mu m fiber amplifiers. Upon excitation at 977 nm laser diode, an intense 1.53-mu m infrared fluorescence has been observed with a broad full width at half maximum (FWHM) of about 60 nm for the Er3+-doped TeO2-BaO (Li2O, Na2O)-La2O3 glass with 10 mol% of BaO. The calculated fluorescence lifetime and the emission cross-sections of the 1.53-mu m transition are 2.91 ms and similar to 9.97 x 10(-21) cm(2), respectively. It is noted that the gain bandwidth, a, x FWHM, of the TeO2-BaO-La2O3Er2O3 glass is about 600, which is significantly higher than that in silicate and phosphate glasses. Meanwhile, it is interesting to note that the TeO2-BaO-La2O3-Er2O3 glass has shown a high glass thermal stability and good infrared transmittance. As a result, TeO2-BaO (Li2O, Na2O)-La2O3 glass with 10 mol% of BaO has been considered to be more useful as a host for broadband optical fiber amplifier. (c) 2005 Elsevier B.V. All rights reserved.

Frequency upconversion properties of Tm3+ doped TeO2-ZnO glasses containing silver nanoparticles

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Frequency upconversion properties of Tm3+ doped TeO2-ZnO glasses containing silver nanoparticles

Frequency upconversion (UC) properties of Tm3+ doped TeO2-ZnO glasses containing silver nanoparticles (NPs) were investigated. Infrared-to-visible and infrared-to-infrared UC processes associated to the Tm3+ ions were studied by exciting the samples with a cw 1050 nm ytterbium laser. The luminescence intensity as a function of laser intensity was also measured using a pulsed 1047 nm Nd3+:YVO laser in order to determine the number of photons participating in the UC processes. Enhancement of the UC signals for samples heat-treated during various time intervals is attributed to the growth of the local field in the vicinity of the NPs. PL enhancement by one-order of magnitude was observed in the whole spectrum of the samples heat-treated during 48 h. On the other hand PL quenching was observed for the samples heat-treated more than 48 h. (c) 2011 Elsevier B.V. All rights reserved.

CuO,CuCl对P2O5-ZnO-Na2O玻璃性质的影响

包边技术是提高大尺寸激光玻璃饱和增益系数的关键。为获得优质包边玻璃,以CuO和CuCl分别作为Cu2+的引入物质,采用传统的玻璃熔制方法,研究了Cu2+掺杂量和不同引入物质对P2O5-ZnO-Na2O体系玻璃形成区、析晶稳定性、物化性能以及吸收系数的影响。研究结果表明,CuO和CuCl都能增大P2O5-ZnO-Na2O体系的玻璃形成区、提高玻璃样品的析晶稳定性。玻璃样品的吸收系数随Cu2+掺杂浓度的增加而明显增大,当Cu2+掺杂摩尔分数达到6%时,样品在1053 nm处的吸收系数为59.46 cm-1,基

Energy transfer and infrared-to-visible upconversion luminescence of Er3+/Yb3+-codoped halide modified tellurite glasses

We report on the energy transfer and frequency upconversion spectroscopic properties of Er3+-doped and Er3+/Yb3+-codoped TeO2-ZnO-Na2O-PbCl2 halide modified tellurite glasses upon excitation with 808 and 978 nm laser diode. Three intense emissions centered at around 529, 546 and 657 nm, alongwith a very weak blue emission at 4 10 nm have clearly been observed for the Er3+/Yb3+-codoped halide modified tellurite glasses upon excitation at 978 nm and the involved mechanisms are explained. The quadratic dependence of fluorescence on excitation laser power confirms the fact that the two-photon contribute to the infrared to green-red upconversion emissions. And the blue upconversion at 410 nm involved a sequential three-photon absorption process. (c) 2005 Elsevier Ltd. All rights reserved.

Estudo das propriedades físicas em materiais vítreos do sistema 50B2O3 - 15CuO - 20Li2O - 15X (X= Na2O, K2O, RbCI e Cs2O)

The increasing demand for devices for solid state applications in many technological areas has resulted in a high demand for new materials. Among these material have the advantage of being manufactured with different chemical compositions, and may have physical properties equal to or higher than the corresponding crystalline material. The aim of this paper was to produce borate glass system 50B2O3 – 15CuO – 20Li2O – 15X (X = Na2O, K2O, RbCl e Cs2O) to analyze the influence of the atomic radius of alkali in the physical properties of this glass system. The glasses were synthesized by the process of melting and molding. The characteristic temperatures were determined by the technique of scanning calorimetry (DSC). The non-crystalline was determined by x-ray diffraction. In order to determine the molar volume a density measurement by using the Archimedes method was used. The structural characterization was carried out using the technique of infrared spectroscopy

Electrical transport characteristics of ZnO-Bi2O3-B2O3 glasses

Optically clear glasses in the ZnO-Bi2O3-B2O3 (ZBBO) system were fabricated via the conventional melt-quenching technique. Dielectric constant and loss measurements carried out on ZBBO glasses unraveled nearly frequency (1 kHz-10 MHz)-independent dielectric characteristics associated with significantly low loss (D = 0.004). However, weak temperature response was found with temperature coefficient of dielectric constant 18 +/- 4 ppm A degrees C-1 in the 35-250 A degrees C temperature range. The conduction and relaxation phenomena were rationalized using universal AC conductivity power law and modulus formalism respectively. The activation energy for relaxation determined using imaginary parts of modulus peaks was 2.54 eV which was close to that of the DC conduction implying the involvement of similar energy barriers in both the processes. Stretched and power exponents were temperature dependent. The relaxation and conduction in these glasses were attributed to the hoping and migration of Bi3+ cations in their own and different local environment.

掺Er^3＋碲酸盐玻璃热稳定性的改进

制备了掺Er^3+-TeO2-ZnO-Na2O-Nb2O5和TeO2-PbO-B2O3系统玻璃，测定了玻璃的热稳定性和吸收光谱，在碲-锌-钠多组分玻璃中具有不同的玻璃转变温度Tg和开始析晶温度Tx，按照Hruby’s参数HR=(Tx-Tg)／(T1-Tc)；(Tx-Tg)越大则玻璃稳定性越好，在TeO2-ZnO-Na2O系统玻璃中ZnO含量增加则(Tx-Tg)增大，加入少量(小于10％(摩尔分数))Nb2O5，PbO使(Tx-Tg)变大，玻璃的热稳定性变好。

Spectroscopic and fluorescence decay behaviors of Yb3+ -doped SiO2-PbO-Na2O-K2O glass

The spectroscopic and fluorescent decay behaviors of Yb3+-doped SiO2-PbO-Na2O-K2O glass is reported in this work. Yb2O3 contents of 1, 1.5 and 2mol% are added into the glass. Through the measurement of absorption and fluorescence spectra, and fluorescent decay rate at room temperature and at low temperature (18 K), it is found that the nonradiative decay rate of Yb3+ ions is mainly determined by the interaction between residual hydroxyl groups and Yb3+ ions. Concentration quenching effect can be omitted in this glass up to the Yb3+ ion concentration of 8.98 x 10(20)/cm(3). Multiphonon decay rate is also very small because of the large energy gap between F-2(5/2) and F-2(7/2) levels of Yb3+ ions. (c) 2004 Elsevier B.V. All rights reserved.

Photoluminescence of undoped and B-doped ZnO in silicate glasses

Photoluminescence of undoped and B-doped ZnO in silicate glasses was investigated by varying the concentration of ZnO (3550 mol%) and B dopant (0-10 mol%) in the glass matrices. The broad and intense near band edge emissions were observed while the visible light emission was very weak. UV luminescence in all samples was red-shifted relative to the exciton transition in bulk ZnO and enhanced by decreased ZnO concentration due to higher degree of structural integrity and the lower aggregation degree of ZnO. Donor B dopant played the double roles of filling conduction bands to broaden band gap when its concentration was lower than 5 mol%, and emerging with conduction bands to narrow the gap when B dopant exceeded this value. (c) 2007 Elsevier B.V. All rights reserved.

Er3+-doped germanate glasses for active waveguides prepared by Ag+/K+ <-> Na+ ion-exchange

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