掺稀土离子液体激光器的研究进展

综合介绍了掺稀土离子液体激光器的主要发展历程，分析了掺稀土离子液体激光材料研究过程中需要解决的主要问题包括降低无辐射跃迁、增大溶解度和减少热致折射率梯度引起的光偏折损耗等。重点介绍了稀土离子在溶液中的无辐射跃迁机理以及降低无辐射跃迁的措施。

三维立体显示用稀土掺杂氧卤碲酸盐玻璃

制备了一种新的Er^3+／Tm^3+/Yb^3+共掺氧卤碲酸盐玻璃。研究了基质玻璃的热稳定性能、Raman光谱和上转换发光。发现：氧卤碲酸盐玻璃具有好的热稳定性能和低的声子能量，在980nmLD激发下，可同时观察到明显的蓝色(476nm)、绿色(530nm和545nm)和红色(656nm)上转换发光。上转换蓝光(476nm)是由于Tm^3+离子1^G4→3^3H6跃迁，上转换的绿光(530nm和545nm)是由于Er^3+离子2^H11/2→4^I15／2和4^S3/2→4^I15/2跃迁，上转换红光(6

Experimental study on a nonlinear photonics process of Er(0.5)Yb(3): FOV oxyfluoride nanophase vitroceramics

We study the nonlinear photonics of rare-earth-doped oxyfluoride nanophase vitroceramics (FOV), oxyfluoride glass (FOG), and ZBLAN fluoride glass. We found that an interesting fluorescence intensity inversion phenomenon between red and green fluorescence occurs from Er(0.5)Yb(3):FOV The dynamic range Sigma of the intensity inversion between red and green fluorescence of Er(0.5)Yb(3):FOV is about 5.753 x 10(2), which is 100 to 1000 times larger than those of other materials. One of the applications of this phenomenon is double-wavelength fluorescence falsification-preventing technology, which is proved to possess the novel antifriction loss and antiscribble properties. (c) 2007 Optical Society of America.

A New Technique for Side Pumping of Double-Clad Fiber Lasers

We report a new technique, called SAP, for side pumping of double-clad, rare-earth-doped fiber lasers using fiber-coupled pump sources. The highest coupling efficiency can even exceed 92% in theory with this structure.

合成方法对几种稀土发光材料的形貌及发光性能的影响

分别采用喷雾热解法、溶胶-凝胶法、共沉淀法和固相法合成了Y<,3>Al<,5>O<,12>:Eu<'3+>发光粉,并且比较了不同方法制备的发光粉的结晶过程和发光性质.通过比较我们发现,与其他三种方法相比,喷雾热解法结晶温度低、合成的发光粉具有球形形貌、且发光强度较大,是一种比较理想的合成发光粉的方法.

氟化物无机纳米粒子的制备及其稀土掺杂体系的光谱性质

对于纳米复合材料来说，首要解决的问题就是光散射。光散射现象主要是粒子尺寸以及粒子与基质材料折射率的差异引起的。对于小粒子（＜25nm），纳米粒子与基质材料之间的折射率差异不会造成明显的光散射现象，但对于较大粒子来说，为避免明显的光散射现象的发生，二者之间的折射必须吻合。由瑞利散射公式计算得知，当粒子直径大到100nm时，粒子与基质之间的折射率差值必须在0.02之内。因此，解决复合材料光散射问题有两种途径：尽量减小纳米粒子尺寸；选择折射率匹配良好的氟化物和聚合物分别作光学活性组分的基质和材料的基底材料。由于微乳液法合成纳米粒子条件温和、设备简单，所合成纳米粒子尺寸可控。本文首先研究了微乳液结构和性质，采用微乳液法合成氟化物纳米粒子，并研究了其稀土掺杂体系的光学性质。对于微乳液结构和性质的研究，本文绘制了十六烷基三甲基嗅化钱（CTAB）／正丁醇（n-C_4H_9OH）／正辛烷（n-C_8H_(18)）／水（或NH4F溶液、或Ba(NO_3)_2溶液、或KNO_3-Mg(NO_3)_2混合溶液）四组分微乳体系的三元相图，观察了电导率随水（或豁溶液）含量变化的规律，很好地印证了微乳液体系的相行为。实验发现，在这四个四元体系的相图中，Ba(NO_3)_2溶液体系的油包水区域面积最大，纯水体系水包油微乳区面积最小，我们分析认为水包油微乳区面积的变化是由于体系中加入离子后对表面活性剂阳离子的静电作用所引起的。采用十六烷基三甲基澳化按（CTAB）／正丁醇／正辛烷／水体系合成了KMgF_3以及KMgF_3:Eu~(2+)纳米粒子。XRD分析表明所合成纳米粒子为立方KMgF_3单相；环境扫描电子显微镜（ESEM）分析得到所合成KMgF_3:Eu~(2+)纳米粒子粒径约为20nm。KMgF_3:Eu~(2+)纳米粒子光谱研究发现其发射峰位于360nm附近，其激发峰位于250nm附近，较KMgF_3:Eu~(2+)单晶的激发峰峰蓝移了约80nm。对KMgF_3:Eu~(2+)纳米粒子激发峰蓝移的机理进行了初步探讨。采用CTAB/2-丁醇／水微乳体系合成出球形BaF_2纳米粒子，XRD和ICP数据显示样品为纯BaF_2相；FTIR谱图证明体系中没有有机物质的存在。将由纳米粒子分散到水中所形成的胶体滴到铜网上，干燥后发现所合成粒子有自组装的特性摘要且粒子自组装形状因粒子尺寸以及样品制备过程而异。粒子的自组装完全是自发的，没有任何的化学试剂对粒子进行包覆，也没对粒子施加除超声分散之外的任何外力。当将一滴胶体溶液直接滴到铜网上，干燥后我们得到粒子的圆形自组装，较大粒子分布在外围形成一个圆，较小粒子分布在圆的内部形成环；我们将一滴BaF_2纳米粒子胶体溶液滴加到铜网上，待干燥后滴加第二滴，重复此操作两次，这样铜网上共滴加的胶体溶液为3滴，此时我们得到粒子的双平行线型组装；直接滴加3滴BaF_2纳米粒子胶体溶液到铜网上，干燥后得粒子的桶状自组装。采用CTAB／正丁醇／正辛烷／水体系于35℃下合成带有枝晶的BaF_2纳米立方。这些枝晶生长在纳米立方的两个相邻面之间呈片状弧形。粉末XRD分析表明，体系为BaF_2单相且结晶良好；用扫描电子显微镜（SEM）对粒子进行分析发现，所得纳米立方边长为400-450nm；FTIR分析表明，经处理后样品中没有有机物质残存；对枝晶的能谱分析（EDS）分析表明，枝晶中只有Ba和F两种元素而未发现C元素存在。这说明，立方上所生长的枝晶为纯BaF_2产物而非有机物质所形成的。试验发现，所合成粒子的尺寸和形状依赖于反应温度和反应时间。采用士一述体系，于25℃下反应，可得到横截面边长40nm，长200nm的立方柱状纳米粒子，并且未见枝晶。从不同反应时间所合成粒子的形状上我们可以估计纳米立方以及枝晶的住：长过程。采用CTAB／正丁醇／正辛烷／水体系首次合成了BaF_2:Er纳米粒子，并研究了掺杂浓度对粒子红外发光的影响，XRD分析表明所合成BaF_2:Er纳米粒子为BaF_2立方相，物相纯净，结晶良好；TEM分析表明在掺杂浓度为6mol％时，粒子尺寸为15-20nm，士曾大粒子的掺杂浓度（8，10和12mol％）下，其尺寸和形状无明显改变，但粒子团聚现象严重。粒子在氢离子激光器488nm激发下的荧光（PL）光谱显示，随粒子掺杂浓度的增大，其发光强度增强，半峰宽加宽。研究了BoF_2:Er纳米粒子尺寸对其发光强度的影响，通过调节体系中水含量以达到控制粒子尺寸的目的。在体系中水含量。分别为5，8，15的条件「分别合成出平均粒径约为8，10和20.5nm的粒子。从粒子的激光粒度分布图中我们可得到粒子的平均尺寸。从粒子的XRD图中我们可以发现，随粒子粒径的减小，粉末的衍射峰出现偏移的情况。对于不同种纳米粒子，粒子粒径越小，衍射峰偏移越严重；对于相同的粒子，衍射角度越大，衍射峰偏移的越严重。从三种粒子的红峰的半峰宽和有效半峰宽越宽，对于8nm粒径的粒子，我们得到其最大半峰宽为145nm或有效半峰宽173nm。而且随粒子粒径的减小，其发射峰出现红移的现象。采用CTAB／正丁醇／正辛烷／水体系首次合成了CeF_3以及掺杂浓度为17，25，30，42和50mol％的CeF_3:Lu纳米粒子。XRD分析表明，所合成纳米粒子为CeF_3六角相，物相纯净，结晶良好，即使在高的掺杂浓度下（50mol％）体系中一也无其他杂质相的存在。环境扫描电子显微镜（ESEM-FEG）分析表明，所合成CeF_3纳米粒子粒径为巧一20nm，Lu的掺入对粒子的形状和尺寸影响不明显，但在较高的掺杂浓度下粒子团聚现象严重。粒子的荧光光谱表明，CeF_3以及Lu：CeF_3纳米粒子在254nm的激发波长下的发射光谱从290nm到400nm的宽带发射，发射峰位于325nm，较单晶体的发射峰红移约30nm；Lu的掺入有利于提高CeF_3纳米粒子的发光强度，随Lu掺入量的增大，粒子的发光强度出现先增后减的情况，在掺杂浓度为30mol％时，我们得到CeF_3纳米粒子的最大发射，但在50mol％的掺杂浓度下的粒子的发射强度仍要比未掺杂体系的发光强度要强。325nln监测粒子的激发光谱是从200nm到350nm的宽带吸收，激发峰峰位于260nm左右。比CeF_3单晶体的280nm激发峰蓝移了20nm左右。而且粒子的激发光谱中未见长波方向上的肩峰，说明粒子中CeF_3纳米粒子结晶良好，且体系中氧含量低。采用自创建一步原位聚合的方法合成了聚合物包覆的纳米粒子，并采用本体聚合的方法合成复合材料。综上所述，本文采用微乳液法合成了不同的氟化物纳米粒子，并研究了其稀土掺杂体系的光学特性，为聚合物基复合材料的制备以及应用奠定了可靠的实验基础。

Luminescent properties of a new blue long-lasting phosphor Ca2P2O7:Eu2+, Y3+

A new pyrophosphate long-lasting phosphor with composition of Ca1.96P2O7:0.02Eu(2+), 0.02Y(3+) is synthesized via the high-temperature solid-state reaction method. Its properties are systematically investigated utilizing XRD, photoluminescence, phosphorescence and thermoluminescence (TL) spectra. The phosphor emits blue light that is related to the characteristic emission of Eu2+ due to 5d-4f transitions. For the optimized sample, bright blue long-lasting phosphorescence (LLP) could be observed by naked eyes even 6 h after the excitation source is removed. The TL spectra show that the doping of Y3+ ions greatly enhanced intensity of 335 K peak and created new TL peak at about 373 K that is also responsible for the blue LLP. Based on our study, Y3+ ions are suggested to act as electron traps to improve the performance of the blue phosphorescence of Eu2+ such as intensity and persistent time.

novel blue-emitting long-lasting proyphosphate phosphor Sr2P2O7:Eu2+, Y3+

By introducing the Y3+ into Sr2P2O7:Eu2+, we successfully prepared a kind of new phosphor with blue long-lasting phosphorescence by the high-temperature solid-state reaction method. In this paper, the properties of Sr2P2O7:Eu2+, Y3+ were investigated utilizing XRD, photoluminescence, luminescence decay, long-lasting phosphorescence and thermoluminescence (TL) spectra. The phosphor emitted blue light that was related to the 4f(6)5d(1)-S-8(7/2) transition of Eu2+. The bright blue phosphorescence could be observed by naked eyes even 8 h after the excitation source was removed. Two TL peaks at 317 and 378 K related to two types of defects appeared in the TL spectrum. By analyzing the TL curve the depths of traps were calculated to be 0.61 and 0.66 eV. Also, the mechanism of LLP was discussed in this report.

Optical spectroscopy and energy transfer of Er3+/Ce3+ in B2O3-doped bismuth-silicate glasses

Ce3+ and B2O3 are introduced into erbium-doped Bi2O3-SiO2 glass to enhance the luminescence emission and optic spectra characters of Er3+. The energy transfer from Er3+ to Ce3+ will obviously be improved with the phonon energy increasing by the addition of B2O3. Here, the nonradiative rate, the lifetime of the I-4(11/2) -> I-4(3/2) transition, and the emission intensity and bandwidth of the 1.5 mu m luminescence with the I-4(13/2) -> I-4(5/2) transition of Er3+ are discussed in detail. The results show that the optical parameters of Er3+ in this bismuth-borate-silicate glass are nearly as good as that in tellurite glass, and the physical properties are similar to those in silicate glass. With the Judd-Ofelt and nonradiative theory analyses, the multiphonon decay and phonon-assisted energy-transfer (PAT) rates are calculated for the Er3+/Ce3+ codoped glasses. For the PAT process, an optimum value of the glass phonon energy is obtained after B2O3 is introduced into the Er3+/Ce3+ codoped bismuth-silicate glasses, and it much improves the energy-transfer rate between Er3+ I-4(11/2)-I-4(13/2) and Ce3+ F-2(5/2) -> F-2(7/2), although there is an energy mismatch. (c) 2007 Optical Society of America.

Effect of OH- on upconversion luminescence of Er3(+)-doped oxyhalide tellurite glasses

The Raman spectra, infrared spectra and upconversion luminescence spectra were studied, and the effect mechanism of OH- groups on the upconversion luminescence of Er3+-doped oxyhalide tellurite glasses was analyzed. The results show that the phonon energy of lead chloride tellurite (PCT) glass was lower than that of lead fluoride tellurite (PFT) glass, but upconversion luminescence intensity of Er3+-doped PFT glass was higher than that of Er3+-doped PCT glass. The analysis considers that it was attributed mainly to the effect of OH- groups. The lower the absorption coefficient of the OH- groups, the higher the fluorescence lifetime of Er3+, and as a result the higher upconversion luminescence intensity of Er3+. In this work, the effect of OH groups on the upconversion luminescence of Er3+ was bigger than that of the phonon energy. (c) 2005 Elsevier Inc. All rights reserved.

Investigation of the effect of fluoride ions introduction on structural, OH- content and up-conversion luminescence properties in Er3+-doped heavy metal oxide glasses

Effect of fluoride ions introduction on structural, OH- content and up-conversion luminescence properties in Er3+-doped heavy metal oxide glasses have been investigated. Structure was investigated, indicating that fluoride has an important influence on the phonon density, maximum phonon energy of host glasses. With increasing fluoride content, the up-conversion luminescence intensity and quantum efficiencies increase notably, which could not be explained only by the maximum phonon energy change of host glasses. Our results show that, with the introduction of PbF2, the decrease of phonon density and OH- content contributes more to the enhanced up-conversion emissions than that of maximum phonon energy. (c) 2005 Elsevier B.V. All rights reserved.

Upconversion luminescence and mechanisms in Yb3+-sensitized Tm3+-doped oxyhalide tellurite glasses

Effect of Yb2O3 content on upconversion luminescence and mechanisms in Yb3+-sensitized Tm3+-doped oxyhalide tellurite glasses were investigated under 980 nm excitation. Intense blue and relatively weak red upconversion emission centered at 476 and 649nm corresponding to the transitions (1)G(4) -> H-3(6) and (1)G(4) -> H-3(4) of Tm3+, respectively, are simultaneously observed at room temperature. The results show that upconversion blue and red emission intensities of Tm3+ first increase, reach its maximum at Yb2O3% = 3 mol%, and then decrease with increasing Yb2O3 content. The effect of Yb2O3 content on upconversion intensity is discussed, and possible effect mechanisms are evaluated. The investigated results were conducing to increase upconversion luminescence efficiency of Tm3+. (c) 2005 Elsevier B.V. All rights reserved.

UV-blue upconverted emission from Nd3+-doped InF3-based heavy-metal fluoride glasses for blue upconversion fibre laser

We report spectral properties and thermal stability of Nd3+-doped InF3-based heavy-metal fluoride glasses. Fluoroindate glasses in the chemical compositions (in mol%) of (38-x)InF3-16BaF(2)-20ZnF(2)-20SrF(2)-3GdF(3)-1GaF(3-)2NaF-xNdF(3) (x = 0.1, 0.5, 1, 2, 3) have been prepared under a controlled atmosphere in a dry box. Strong UVblue upconversion emission from a green excitation wavelength has been observed and the involved mechanisms have been explained. Near-infrared emission occurs simultaneously upon excitation of the UV-blue upconversion emissions with a cw Ar(+)laser. The upconversion spectra have revealed four dominant emissions at 354, 380, 412 and 449 nm, which belong to the transitions of D-4(3/2) -> I-4(9/2), D-4(3/2) -> I-4(11/2) and P-2(3/2) -> I-4(9/2), D-4(3/2) -> I-4(13/2) and P-2(3/2) -> I-4(11/2), D-4(3/2) -> I-4(15/2) and P-2(3/2) -> I-4(13/2), respectively.

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.

Effect of network modifiers on spectroscopic properties of erbium-doped phosphate glasses

The integrated absorption cross section Sigma(abs), I peak emission cross section sigma(cmi), Judd-Ofeld intensity parameters Omega(iota) ( t = 2,4,6), and spontaneous emission probability A(R) of Er3+ ions were determined for Erbium doped alkali and alkaline earth phosphate glasses. It is found the compositional dependence of sigma(emi) 5 almost similar to that of Sigma(abs), which is determined by the sum, of Omega(1) (3 Omega(2) + 10 Omega(4) + 21 Omega(6)). In addition, the compositional dependence of Omega(1) was studied in these glass systems. As a result, compared with. Omega(4) and Omega(6) the Omega(2) has a stronger compositional dependence on the ionic radius and content of modifers. The covalency of Er-O bonds in phosphate glass is weaker than that in silicate glass, germanate glass, aluminate glass, and tellurate glass, since Omega(6) of phosphate glass is relatively large. A(R) is affected by the covalency of the Er3+ ion sites and corresponds to the Omega(6) value.