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1.
The effects of Al2O3, Yb2O3, Er2O3 and OH on spectral properties of P2O5·Na2O·SrO·Al2O3·Yb2O3·Er2O3 erbium phosphate glass were studied. 5, 8, 13 mol% Al2O3, 4, 5, 6, 7 and 8 mol% Yb2O3 and 0.05, 0.2, 0.4 mol% Er2O3 were used. It was found Al2O3 improves fluorescent lifetime of Er3+ ions, but the integrated absorption cross-section of Er3+ ions decreases with the increase of Al2O3 concentration. Evaluating from energy transfer efficiency of Yb3+ to Er3+ and spectral parameters of Yb3+ and Er3+, lower Al2O3 content, 6 mol% Yb2O3 and 0.2–0.4 mol% Er2O3 are preferred for LD pumped microchip laser application. OH groups in glass greatly affect fluorescent intensity and lifetime of Er3+, Yb3+:phosphate glass. The OH absorption coefficient at 3000 cm−1 should be <1 cm−1 for laser applications. Pumped with a 2 W, 974 nm InGaAs laser diode, CW laser centered at 1530 nm with slope efficiency of 10.6% and maximum output of 43 mW was achieved in our 2 mm thick Er3+, Yb3+:phosphate glass at room temperature. 相似文献
2.
通过化学沉淀法引入烧结助剂Y3+、La3+和Mg2+, 采用真空烧结工艺制备了半透明Al2O3陶瓷, 并研究了烧结助剂对烧结材料的微观结构、相对密度和透光率的影响。结果表明: 引入的烧结助剂能均匀分散在合成的半透明Al2O3陶瓷中。烧结助剂的最佳引入量为Mg2+(0.15wt%)、Y3+(0.05wt%)和La3+(0.05wt%), 对应的试样在350~800 nm的波长范围内显示出的最高的总透光率(TFT)高于80%。此外, Y3+的掺杂可以促进晶粒生长, 降低孔隙率, 从而提高半透明Al2O3陶瓷的透光率。 相似文献
3.
1 mol%Er3+–10 mol%Yb3+ codoped Al2O3 thin films have been prepared on thermally oxidized SiO2/Si(110) substrates by a dip-coating process in the non-aqueous sol–gel method from the hydrolysis of aluminum isopropoxide [Al(OC3H7)3] under isopropanol environment. Addition of N,N-dimethylformamide (DMF) as a drying control chemical additive (DCCA) into the sol suppresses formation of the cracks in the Er3+–Yb3+ codoped Al2O3 thin films when the rare-earth ion is doped with a high doping concentration. Homogeneous, smooth and crack-free Er3+–Yb3+ codoped Al2O3 thin films form at the conditions by a molar ratio of 1:1 for DMF:Al(OC3H7)3. A strong photoluminescence spectrum with a broadband extending from 1.400 to 1.700 µm centered at 1.533 µm is obtained for the Er3+–Yb3+ codoped Al2O3 thin films, which is unrelated to the addition of DMF. Controllable formation of the Er3+–Yb3+ codoped Al2O3 thin films may be explained by the fact that the DMF assisted the deprotonation process of Al–OH at the surfaces of gel particles, resulting in enhancement of the degree of polymerization of sols and improvement of the mechanical properties of gel thin films. 相似文献
4.
Rate equations formalism is used to predict the population ratio of the Er3+ 4I13/2 levels involved in the 1.55 μm laser transition in the Yb:Er:CAS laser materials. An effective Yb → Er energy transfer, favourable to the Er3+ 1.55 μm laser emission, is demonstrated in this laser host. Indeed, the Yb → Er transfer and the Er → Yb back transfer rates are calculated to be 6 x 10−16 and 0.45 x 10−16 cm3 s−1, respectively. Attempts of codoping the system with Nd3+, Eu3+ and Ce3+ have been realised in order to increase the population of the Er3+ 4I13/2 laser emitting level. Best results are obtained with Ce3+ ion since in the sample containing 6 x 1020 Ce3+/cm3, the Er3+ 4I11/2 level lifetime is divided by a factor of 3 while the Er3+ 4I13/2 fluorescence lifetime remains unaffected. On the contrary, codoping with Nd3+ or Eu3+ ions simultaneously decreases the Er3+ 4I11/2 and 4I13/2 kinetics parameters. The role of the other parameters such as Yb/Er concentrations ratios is also discussed. 相似文献
5.
采用溶胶-凝胶法结合高温真空烧结工艺制备了不同浓度的Al3+/Yb3+/P5+掺杂石英玻璃。研究了P5+和Al3+的引入对Yb3+掺杂石英玻璃紫外透过和紫外激发荧光光谱, 以及Yb4d电子结合能的影响, 并初步探索了其机理。研究结果表明, Al3+/Yb3+/P5+掺杂石英玻璃在190~300 nm波段的吸收主要来源于O2-→Yb3+的电荷迁移吸收, 其谱带位置和Yb4d电子结合能随Yb3+的第二配位元素(Al、Si、P)电负性增大向高能方向移动。真空烧结条件下, 引入Al3+会引发石英玻璃中Yb3+还原为Yb2+, 其典型的吸收峰位于330 nm处; 然而, 在Al3+/Yb3+共掺的基础上再引入P5+, 且P5+/Al3+摩尔比大于1时, 可以有效抑制Yb2+的形成。紫外光激发引起的近红外发光(976 nm)是电子从电荷迁移态弛豫到Yb3+激发态向基态跃迁的结果, 可见发光(525 nm)归因于Yb2+的5d→4f跃迁。本文研究结果对通过优化工艺和调整组分制备出高性能的Yb3+掺杂光纤具有一定的指导意义。 相似文献
6.
按照0.71Pb(Mg1/3Nb2/3)O3-0.26PbTiO3-0.03Pb(Er1/2Nb1/2)O3化学式所示组分比例, 采用分步高温固相反应合成出Er3+掺杂PMNT多晶, 通过熔体坩埚下降法生长出尺寸φ25 mm×100 mm的Er3+掺杂PMNT晶体, Er3+离子以三元固溶体组元方式被掺杂进入钙钛矿相铁电体晶格; 测试了Er3+掺杂PMNT晶片的介电、压电与铁电性能以及上转换发光性能。结果表明, Er3+掺杂PMNT晶体呈现跟三方相纯PMNT晶体相近的介电、压电与铁电性能; 在980 nm激发光作用下, 该掺杂晶体呈现出Er3+离子特有的较强上转换荧光发射, 并且极化后掺杂晶体的上转换发光强度得到增强。 相似文献
7.
Nobuko Maeda Noriyuki Wada Hiroaki Onoda Akira Maegawa Kazuo Kojima 《Optical Materials》2005,27(12):1851-1858
Thin films of the system xAl2O3–(100 − x)Ta2O5–1Er2O3 were prepared by a sol–gel method and a dip-coating technique. The influences of the composition and the crystallization of the films on Er3+ optical properties were investigated. Results of X-ray diffraction indicated that the crystallization temperature of Ta2O5 increased from 800 to 1000 °C with increased values of x. In crystallized films, the intensities of the visible fluorescence and upconversion fluorescence tend to decrease with an increase in x values, due to the high phonon energy of Al2O3; the strongest fluorescence is observed in a crystallized film for x = 4 heat treated at 1000 °C. In amorphous films obtained by heat treatment at relatively low temperatures the Er3+ fluorescence could not be observed because strong fluorescence from organic residues remaining in the films thoroughly covered the Er3+ fluorescence. On the other hand, the Er3+ upconversion fluorescence in the amorphous films was observed to be stronger than that in the crystallized films. The strongest upconversion fluorescence is observed in an amorphous film for x = 75 heat treated at 800 °C. 相似文献
8.
In this work, the LaOBr:Er3+ (0.1%) powders were prepared by solid state reaction. The structural properties of LaOBr:Er3+ were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. The results show that LaOBr:Er3+ has low phonon energy, which indicate that LaOBr:Er3+ may have high luminescent efficiency. Under excitation into 4I11/2 level of Er3+ ions by 980 nm laser, the two- and three-photon upconverted luminescence of LaOBr:Er3+ were recorded. The most intense emissions were come from the 2H11/2, 4S3/2 → 4I15/2 transitions. The upconversion mechanisms were studied in detail through laser power dependence, and results show that excited state absorption is responsible for the upconversion. The upconversion properties indicate that LaOBr:Er3+ may be used in upconversion phosphors. 相似文献
9.
以菱镁矿风化石、工业Al2O3和SiO2微粉为原料, 固相反应烧结合成制备堇青石。通过在反应物中分别加入不同含量的Eu2O3、Dy2O3和Er2O3, 研究分析和对比了Eu3+、Dy3+和Er3+对堇青石晶相组成、晶粒大小、晶胞常数、结晶度及显微结构的影响。采用XRD和SEM表征试样中的晶相和显微结构, 利用X'Pert Plus软件对结晶相的晶胞参数和结晶度进行分析, 采用半定量法对试样晶相组成进行计算, 利用Scherrer公式计算堇青石的晶粒大小。结果表明: 由于Eu2O3、Dy2O3和Er2O3的加入, 通过固相反应烧结所得堇青石试样中出现了莫来石相, Eu3+、Dy3+和Er3+对Mg2+的置换作用改变了堇青石相晶格常数和晶胞体积。随着添加剂含量的增加, 堇青石结构中液相量增加, 相对结晶度降低, 常温致密度提高, 堇青石晶粒粒径减小。综合对比分析, Eu2O3对堇青石晶相转变的影响程度最弱, Er2O3对堇青石晶相转变的影响程度最强, 对提高合成堇青石的烧结性和热震稳定性效果最好。 相似文献
10.
The effect of radiation trapping on the emission properties of Er3+-doped tellurite and phosphate glasses has been investigated as the function of sample thickness and doping concentration. It was found that radiation trapping exists generally in two glass matrices, even at low doping concentration (0.1 mol% Er2O3). The larger effect of radiation trapping in tellurite glasses compared with phosphate glasses is due to its larger emission cross-section at 1.5 μm band and the spectral overlap between the emission and absorption spectra of Er3+: 4I13/2 ↔ 4I15/2transition. Due to radiation trapping, the measured lifetime of the Er3+: 4I13/2 level in tellurite glasses increases by about 11–37% with increasing the sample thickness at the different erbium doping concentration, while 6–17% for phosphate glasses. And the full-width at half maximum of fluorescence (FWHM) of Er3+: 4I13/2 → 4I15/2 transition in tellurite glasses increased by about 15–64% with increasing the sample thickness, while 11–55% for phosphate glasses. It caused a high overestimation on the figure of merits (FOM) for amplifier bandwidth (σe × FWHM). 相似文献
11.
采用3种不同形貌的Al2O3原料对注凝成型制备ZrO2/Al2O3(ZTA)陶瓷工艺中悬浮体的流变性能进行了研究。以低毒的单体N,N-二甲基丙烯酰胺(DMAA)制备了ZrO2/Al2O3坯体和陶瓷。讨论了3种不同形貌的Al2O3原浆料的分散剂用量、球磨时间和固含量对浆料流变性的影响。Al2O3粉体呈扁平状有利于降低浆料的黏度,Al2O3粉体呈棒状对生坯强度的提高有利。制得的3种ZrO2/Al2O3坯体颗粒间结合紧密,抗弯强度分别达到21.45,19.87,25.90 MPa。Al2O3粉体呈颗粒状有利于最终陶瓷力学性能的提高,陶瓷的抗弯强度及断裂韧性分别为680 MPa和7.49 MPa·m1/2,453.1 MPa和6.8 MPa·m1/2,549.4 MPa和6.34 MPa·m1/2。 相似文献
12.
We report measurements of the energy transfer between Er3+ and Ce3+ in Y2O3. The transition between the Er3+ 4I11/2 and 4I13/2 excited states can be stimulated by energy transfer to Ce3+, augmenting the population in the 4I13/2 state at the expense of that in the 4I11/2 state. Experiments were performed on Y2O3 planar waveguides doped with 0.2 at.% erbium and 0–0.42 at.% cerium by ion implantation. From measurements of Er3+ decay rates as a function of cerium concentration we derive an energy transfer rate constant of 1.3×10−18 cm3/s. The efficiency of the energy transfer amounts to 0.47 at 0.42 at.% cerium. The energy transfer rate constant measured in Y2O3 is two times smaller for Er3+→Ce3+ than that for Er3+→Eu3+ in the same material. 相似文献
13.
实验制备了Ni2+掺杂的ZnO-MgO-Al2O3-SiO2(ZMAS)体系的透明微晶玻璃, 研究了微晶玻璃的超宽带发光现象。热分析结果表明样品的玻璃化转变温度(Tg)和析晶峰温度(Tc)分别为754℃和948℃。采用X射线粉末衍射分析了两种热处理制度对玻璃的晶体形核、晶体生长及物相变化的影响, 结果表明: 采用阶梯温度热处理制度可以得到Ni2+掺杂的尖晶石相透明微晶玻璃。紫外-可见吸收光谱和荧光光谱测试表明制备的Ni2+掺杂ZMAS微晶玻璃中Ni2+以四配位和六配位共同存在于尖晶石相中, 红外荧光中心位于1324 nm的样品荧光半高宽达490 nm。样品的超宽带荧光主要是由于微晶玻璃中六配位Ni2+在ZnAl2O4和MgAl2O4形成的尖晶石相固溶体晶体场中的3T2g(3F)→3A2g(3F) 能级跃迁。实验结果表明, 制备的微晶玻璃在超宽带光纤放大器等光子器件中具有潜在的应用前景。 相似文献
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利用无容器技术制备了(La0.94-xEr0.06Ybx)(Ti0.95Zr0.05)2.25O6(x=0~0.24, 间隔0.04)球状透明玻璃, 其稀土离子掺杂浓度最大值达到30%。通过DTA分析发现, 玻璃具有很好的热稳定性, x=0时玻璃化转变温度Tg和析晶起始温度To分别为818℃和906℃, ΔT(ΔT= To-Tg)为88℃, 玻璃形成能力较低。随着Yb3+浓度提高, Tg、To和ΔT逐渐下降, 说明Yb3+降低了玻璃的热稳定性和形成能力。利用紫外可见分光光度计测定了样品的吸收/透过光谱, 玻璃在975 nm具有很强的吸收峰, 表明Yb3+可以有效提高玻璃对入射光的吸收强度; 在可见光范围内除特征吸收外具有近70%的透过率, 说明玻璃具有良好的透可见光性能, 有望获得高强上转换发光输出。上转换荧光光谱研究表明: 在980 nm激光泵浦下, 获得了中心位于535、554和672 nm处的绿、红发光带, x=0.16的发光最强, 672 nm处的红光强度是x=0的近130倍。上转换发光强度与泵浦功率关系的分析表明: 535、554 nm处的绿光和672 nm处的红光发光均是双光子发光过程。 相似文献
15.
Dense TiC–Al2O3–Al composite was prepared with Al, C and TiO2 powders by means of electric field-activated combustion synthesis and infiltration of the molten metal (here Al) into the synthesized TiC–Al2O3 ceramic. An external electric field can effectively improve the adiabatic combustion temperature of the reactive system and overcome the thermodynamic limitation of reaction with x < 10 mol. Thereby, it can induce a self-sustaining combustion synthesis process. During the formation of Al2O3–TiC–Al composite, Al is molten first, and reacted with TiO2 to form Al2O3, followed by the formation of TiC through the reaction between the displaced Ti and C. Highly dense TiC–Al2O3–Al with relative density of up to 92.5% was directly fabricated with the application of a 14 mol excess Al content and a 25 V cm−1 field strength, in which TiC and Al2O3 particles possess fine-structured sizes of 0.2–1.0 μm, with uniform distribution in metal Al. The hardness, bending strength and fracture toughness of the synthesized TiC–Al2O3–Al composite are 56.5 GPa, 531 MPa and 10.96 MPa m1/2, respectively. 相似文献
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17.
In the hexaaluminate laser material La0.9Nd0.1MgAl11O19 also known as LMA:Nd the Nd3+ fluorescence can be enhanced by codoping the matrix with rare-earth (REn+) or transition metal (TMm+) ions. A large number of potential donor ions D (D = Mn2+, Dy3+, Tb3+, Eu2+, Eu3+ and Ti3+) are studied in the hexaaluminate host. The D→Nd3+ energy transfer, t he, luminescent efficiency as well as the back-transfer strongly depend on the overlap of the D emission and Nd3+ absorption, the concentration of the two ions and their localization in the crystal host. In this paper the optical properties — absorption and emission — of the D and Nd3+ ions as well as the D→Nd3+ interactions are considered using a Forster-Dexter's approach, to compare the capabilities of the different donors in the Nd3+-doped hexaaluminate host. The CDNd and R0 parameters are estimated in each case, and the results discussed in terms of the localization of the donor ions, their absorption and emission as well as their lifetime properties. 相似文献
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为了得到最优发光的薄膜材料成分参数,采用均匀设计和二次通用旋转组合设计相结合的方法建立发光强度与薄膜中氧含量和Ce3+ 离子掺杂浓度的回归方程,并用遗传算法求其取最大值时的解。用中频反应磁控溅射技术制备了相应成分的Al2O3:Ce非晶薄膜。在320nm光激发下,获得了较理想的发射光谱,对薄膜发光机理分析表明:薄膜的光致发光来自于Ce3+ 离子的5d1激发态向基态4f1的两个劈裂能级的跃迁。发光强度强烈的依赖于薄膜的掺杂浓度和氧元素含量。XPS检测表明,Al2O3:Ce薄膜中存在Ce3+ 。Ce3+ 含量和薄膜的化学成分是通过X射线散射能谱(EDS)测量的。薄膜试样的晶体结构应用X射线衍射分析。 相似文献
20.
使用熔融淬冷法制备了Er3+掺杂Ge-Ga-S-CsBr硫卤玻璃, 研究了其在1550 nm激光激发下的上转换发光特性, 观察到强的波长中心位于525和545 nm绿色发光及弱的中心波长位于660 nm红色发光, 也观察到了中心波长分别位于810和980 nm的红外上转换发光。基于泵探光功率关系和能级寿命测试研究了发光机理, 发现中间态能级寿命的延长是上转换发光效率增强的根本原因。使用全光谱光源测试了Si太阳能效率, 当使用上转换发光层时, 太阳能电池平均效率从7.28%上升至7.32%。结果显示所探索的稀土掺杂硫卤玻璃有望应用于硅太阳能电池效率增强领域。 相似文献