Optical amplification of Eu(DBM)3Phen-doped polymer optical fiber

A preform technique is used to prepare a step-index (SI) polymer optical fiber (POF) doped with Eu(DBM)3Phen. The gain (5.7 dB) at 613 nm of the doped SI POF with Eu3+ content of 4000 in 10(6) wt., 0.4-mm core diameter, and 30-cm fiber length is observed at ambient temperature by end pumping with a YAG at 355 nm. The input signal light is approximately 0.2 W. The results show the possibility of signal gain in a rare-earth-doped POF amplifier and the potential of a polymer doped with rare-earth ions as an active optical device.     

Synthesis and luminescent properties of complexes of Eu(III) with 2-thienyltrifluoroacetonate, terephthalic acid and phenanthroline

This work reports the synthesis and luminescent properties of complexes of europium(III) with 2-thienyltrifluoroacetonate (HTTA), terephthalic acid (TPA) and phenanthroline (Phen), in the solid state. The new complexes were characterized by elemental analysis, infrared (IR) spectroscopy, scanning electronic microscopy (SEM) and thermal stability analysis. Both binuclear complex Eu₂(TPA)(TTA)₄Phen₂ and polynuclear complex Eu(TPA)(TTA)Phen present better thermal stability than the mononuclear complex Eu(TTA)₃Phen does. The formation of the binuclear/polynuclear structure of the complexes appears to be responsible for the enhancement of the thermal stability. The emission spectra show narrow emission bands that arise from the ⁵D₀→⁷F_J (J=0-4) transition of the Eu³⁺ ion. The spectral data of the complexes Eu(TPA)(TTA)Phen and Eu₂(TPA)(TTA)₄Phen₂ present only one sharp peak in the region of the ⁵D₀→⁷F₀ transition indicating that only one Eu³⁺ ion species is present in each sample. In addition, the luminescence decay curves of the complexes Eu(TPA)(TTA)Phen and Eu₂(TPA)(TTA)₄Phen₂ fit a single-exponential decay law. The values of quantum efficiencies of the emitting ⁵D₀ level for the complexes Eu(TPA)(TTA)Phen and Eu₂(TPA)(TTA)₄Phen₂ are 29% and 28%, respectively.     

Assemblies, characterization, and luminescent enhancement of organized molecular films based on rare earth complexes

Langmuir-Blodgett (LB) films of different molar percentages of Eu(TTA)₃Phen (TTA=2-thenoyltrifluoroacetone; Phen=1,10-phenanthroline) with Gd(TTA)₃Phen coexisting with arachidic acid (AA) (complexes:AA=1:l, in molar ratio) were fabricated and the luminescence enhancement of Eu(III) in the films was studied in this investigation. The monolayers and LB films were characterized by π-A isotherms, fluorescence microscopy, UV-vis spectroscopy and low-angle X-ray diffraction. High-quality LB films and strongly luminescent films were obtained. It was learned from the present study that an efficient intermolecular energy transfer occurred from Gd(TTA)₃Phen to Eu(TTA)₃Phen in the films, which resulted in the luminescence enhancement effect. According to the proposed model of the “active enhancement circle” the distance of energy transfer from Gd-, Tb-, La-, and Y-complex to Eu-complex were calculated to be 1.2, 1.2, 0.7 and 1.0 nm, respectively.     

Analysis on fluorescence of dual excitable Eu(TTA)3DPBT in toluene solution and PMMA

Photoluminescence of Eu(TTA)₃DPBT (TTA=thenoyltrifluoro-acetonate DPBT=2-(N,N-diethylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine) in toluene and PMMA thin film are measured with excitation at 350 and 404 nm, respectively, and analyzed using Judd-Ofelt theory. Under excitation at 350 nm, it is found that Eu(TTA)₃DPBT in toluene has a larger Ω₂ value (14.33×10⁻²⁰ cm²) than that (12.70×10⁻²⁰ cm²) of Eu(TTA)₃Phen (Phen=1,10-phenanthroline) in the same solvent, and has a smaller Ω₂ value (12.70×10⁻²⁰ cm²) in PMMA than that (Ω₂=14.09×10⁻²⁰ cm²) of Eu(TTA)₃Phen in PMMA. At the same time, it can be seen that under excitation at 350 nm Ω₂ value of Eu(TTA)₃DPBT in toluene is larger than that in PMMA. Excited by 404 nm, Ω₂ of Eu(TTA)₃DPBT obtained in toluene and in PMMA are the same as that excited at 350 nm. The transition probability (A), emission cross-section (σ) and the fluorescence branching ratio (β) are also evaluated. The lifetime of ⁵D₀ metastable state is measured on 350 and 404 nm excitation, respectively. For the former situation, it is 455 μs in toluene and 640 μs in PMMA, for the latter it is 460 μs in toluene and 664 μs in PMMA. By comparing absorptions with excitations, it can be found that DPBT is more efficient than TTA as an energy donor. Phosphorescence spectra are also measured to estimate the lowest triplet level and analyze the energy transfer for DPBT and TTA, from which it is found that the energy transfer from TTA to DPBT occurs in the luminescent process.     

铕铽共掺稀土聚合物的光谱分析及发光性能研究

合成了一种新型的稀土配合物Eu_0.5Tb_0.5(TTA)₃Phen,并采用原位乳液聚合法进一步制备了Eu_0.5Tb_0.5(TTA)₃Phen/PMMA稀土聚合物。利用红外光谱仪(IR)、电子探针X射线能谱仪等对其结构进行了表征,利用扫描隧道电子显微镜(SEM)、荧光光谱仪(FS)等研究了其微观形貌,并探讨了其发光性能。结果表明,聚合物中PMMA与稀土部分Eu_0.5Tb_0.5(TTA)₃Phen通过键合的方式结合, 仍保持Eu0.5Tb_0.5(TTA)₃Phen原有的发光特性;在365 nm紫外光的激发下,产生发光峰在611.8 nm附近、谱线带宽为10.4 nm的红光发射,发光亮度高,色纯度高;Eu_0.5Tb_0.5(TTA)₃Phen/PMMA具有良好的发光性能,其发光强度与MMA加入的含量有关。     

Random fiber laser of POSS solution-filled hollow optical fiber by end pumping

Random fiber laser is obtained by end pumping a hollow optical fiber (HOF) filled with a dispersive solution of polyhedral oligomeric silsesquioxanes (POSS) nanoparticles and laser dye pyrromethene 597 (PM597) in carbon disulfide (CS₂), in which the concentration is 1.5×10^?2 M for PM597 and 18.5 wt% for POSS, respectively. It is found that the pump light at the one end of the liquid core optical fiber (LCOF) can pass the whole length of LCOF because the POSS nanoparticles were dispersed in CS₂ at a molecular level (1–3 nm) with high stability and without sedimentation. Above the threshold pump energy (～0.81 mJ) the random fiber laser appears coherent and resonant feedback multimode lasing in the weakly scattering system. For the LCOF containing PM597 with the same concentration and no POSS nanoparticles, there occurs only ASE that can be observed under the same experimental condition.     

Eu(DBM)_3Phen掺杂聚甲基丙烯酸甲酯静电纺丝荧光纤维

通过静电纺丝技术获得直径约为700 nm,均匀且随机取向的亚微米级Eu(DBM)3Phen/PMMA纤维。在紫外光辐射下,亚微米级荧光纤维发出明亮的红色荧光。其激发光谱表明,荧光纤维有效激发波长范围为200~400 nm。利用积分球配以CCD探测器,在367 nm长波紫外LED激发下对荧光纤维开展绝对光谱功率测试。当LED泵浦功率为535.76#W时,厚度80#m的Eu(DBM)3Phen/PMMA纤维薄层对紫外辐射的吸收率高达89%,350~850 nm范围内发射的总绝对光谱功率、总光子数和总荧光量子产率分别为36.56#W、11.46×10~(13)cps和12.94%。亚微米级Eu(DBM)_3Phen/PMMA纤维薄层中,Eu~(3+)较高的跃迁发射几率及较大的发射截面使得纤维可以高效吸收紫外辐射并转变为可见光,在提高太阳能电池光电转换效率方面具有潜在应用价值。     

Fabrication and amplified spontaneous emission of Eu(DBM) <Subscript>3</Subscript>Phen doped step-index polymer optical fiber

A step-index polymer optical fiber (SI POF) with a core of poly(methyl methacrylate) (PMMA) containing Eu(DBM)₃Phen has been fabricated by a preform technique. Fluorescence analysis showed that there is not obvious change in the local environment around Eu³⁺with the increase of Eu(DBM)₃Phen doping concentration. Amplified spontaneous emission (ASE) phenomenon of the doped SI POF by end-pumping with an Ar⁺-laser of 457.9 nm at ambient temperature was observed. The threshold of the pump power for the onset of ASE is found to be 120 mW for the doped SI POF with a length of 50 cm, the length is also found to be the optimal length for maximum ASE power under the input power of 200 mW. The maximum quantum conversion efficiency of the fiber is about 40%.     

Development of electroluminescence cell using a Eu0.5Y0.5(TTA)3Phen organic luminescent complex

Novel red emitting organic luminescent complexes, namely Eu_0.5Ln_0.5(TTA)₃ Phen (Eu: europium, Ln: Y/Tb, Y: yttrium, Tb: terbium, TTA: thenoyl tri fluoro acetone, Phen: phenanthroline) were synthesized by solution technique, maintaining stoichiometric ratio. These complexes were characterized by various techniques such as XRD, optical absorption and photoluminescence (PL) spectra. Electroluminescence cells were designed by sandwiching Eu_0.5Ln_0.5(TTA)₃Phen between indium tin oxide (ITO) and aluminum (Al). Voltage?current characteristics and voltage?brightness characteristics of the developed electroluminescent cell were carried out. Turn on voltage of both the devices was found to be 9 V. These devices emit intense red emission at 611 nm, proving their potential applications as organic light emitting diodes and displays.     

罗丹明B荧光增强苯受激拉曼散射研究

将液芯光纤技术与荧光增强受激拉曼散射技术相结合,能够大大增强受激拉曼散射光谱强度,降低受激拉曼散射阈值。通过对罗丹明B苯溶液在液芯光纤中的受激拉曼散射进行研究,结果表明:荧光染料Rhodamine B可以降低苯溶液的各阶受激拉曼散射阈值近一个数量级;在一定浓度范围内(10-6mol/L~10-8mol/L)各阶Stokes阈值随浓度降低而降低,并在理论上给出了解释。并且理论推导了在荧光种子作用下的四阶耦合波方程。液芯光纤中的受激拉曼光谱技术在对实现宽带受激辐射激光器、种子激光,以及生物大分子结构研究、生物分子的非生物过程研究等领域等有光明应用前景。     

Electrospinning preparation and photophysical properties of one-dimensional (1D) composite nanofibers doped with erbium(III) complexes

1D composite nanofibers of poly(vinylpyrrolidone) (PVP, M_W≈60,000) doped with three Er(III) complexes were prepared by electrospinning. They demonstrated strong near-infrared (NIR) photoluminescence (PL) at 1535 nm and ternary Er(TTA)₃Phen (denoted as Er2, where TTA=2-thenoyltrifluoroacetonate; Phen=1,10-phenanthroline) fibers (Er2/PVP) exhibited maximum PL intensity. The crystal structure of Er2 complex has been determined by X-ray diffraction measurements. Er2 doped in fibers exhibited better thermal stability of NIR PL than the pure Er2 complex. These luminescent composite fibers have potential application in optical amplifiers.     

Influencing factors of external fluorescence seeding enhancing stimulated Raman scattering in liquid‐core optical fiber

This paper reports an external fluorescence seeding technology enhancing the stimulated Raman scattering (SRS) in liquid‐core optical fiber (LCOF). By surrounding a small section of LCOF with a glass capillary and a solution of Rhodamine 6G filled between them to separate fluorescent dye and Raman medium, the initial intensity of SRS is linearly amplified by external fluorescence seeding, and then the SRS of LCOF can be enhanced effectively. Experimental results show that both the concentration of fluorescent dye and the seeding position have an influence on enhancement of SRS. The maximum enhancement of Stokes lines is obtained when the concentration of dye solution is optimized at ~10⁻⁶ mol/l and seeding position is located at the input end. Copyright © 2013 John Wiley & Sons, Ltd.     

一种新型稀土配合物Eu(TTA)(2NH_2-Phen)_3的发光特性研究

合成了一种新型的稀土配合物Eu(TTA)(2NH_2-Phen)_3,将其作为掺杂物与基质聚乙烯基咔唑(PVK)按照不同质量比混合共溶,旋涂成膜.测量了混合薄膜的光致发光光谱,确认了所合成的Eu(TTA)(2NH_2H-Phen)_3具有发射荧光的能力,进而将其应用于电致发光器件中.还制备了以PVK:Eu(TTA)(2NH_2-Phen)_3为发光层,器件结构为ITO/PVK:Eu(TTA)(2NH_2-Phen)3/2,9-dimethy1-4,-diphenyl-1,10-plaenan thmline(BCP)/8-hydroxyquinoline aluminum(Alq_3)/Al的多层器件,得到了 Eu~(3+)的红色电敛发光.研究不同掺杂浓度时器件发光光谱的变化及PVK的发射光谱与Eu(TTA)(2NH_2-Phen)_3的吸收光谱的交叠情况,证明了混合薄膜中Eu~(3+)电致发光机理主要足载流子的直接俘获.     

Research on Raman spectrum in liquid core optical fiber of CCl4 solution

The Raman spectrum intensity can be enhanced in liquid core optical fiber (LCOF) of CCl4 solution.We dissolved liquid CCl4 into CS2 and got solutions of different concentrations. There is an optimum concentration at which the maximum Raman intensity can be obtained. There exists an optimum fiber length of 2 m. The experimental result is in good agreement with the theoretical calculation. The Raman intensity becomes powerful with the increase of the pump power and Raman linewidth becomes narrower with the decrease of the CCl4 concentration.     

Stimulated Brillouin scattering with high reflectivity and fidelity in liquid-core optical fibers

The characteristics of stimulated Brillouin scattering (SBS) in a liquid-core optical fiber (LCOF) contained CS₂ with 10?ns pulses at 532?nm wavelength are investigated experimentally. The threshold, reflectivity, pulse-shape (PS) fidelity, and phase-conjugation (PC) fidelity of LCOFs with different core diameters and lengths are measured. Threshold energy is as low as 2.5???J, and the SBS reflectivity, the PS fidelity, and PC fidelity exceed simultaneously 90?% when the input energy is over 20 times threshold.     

偏苯三甲酸铕（Ⅲ）系列四元配合物的合成及相关性能研究

合成了Eu（Ⅲ）与偏苯三甲酸（TLA）、2-噻酚甲酰三氟丙酮（HTTA）和邻菲罗啉（Phen）形成的两个新的四元配合物。运用元素分析、红外光谱、扫描电镜、热重与荧光光谱等手段对它们进行了系统的表征。研究结果表明,偏苯三甲酸与2-噻酚甲酰三氟丙酮Eu（Ⅲ）和邻菲罗啉形成的四元配合物,具有比偏苯三甲酸Eu（Ⅲ）和邻菲罗啉形成的三元配合物更强的荧光强度与更宽的紫外激发,比配合物Eu（TTA）3Phen更好的热稳定性。得到了两种热稳定性较好的鲜艳红色荧光材料。     

二氧化硅包覆稀土配合物Eu(TTA)3phen制备及其荧光性能研究

将稀土配合物Eu(TTA)3phen分散于异丙醇中,通过水解正硅酸乙酯(TEOS)的方法制备了新型荧光材料二氧化硅包覆稀土配合物SiO2/Eu(TTA)3phen.荧光光谱表明二氧化硅包覆后的稀土配合物荧光强度增加了将近一倍,同时,发现Eu3+在617.4 nm附近的发射峰变得非常尖锐,而未经二氧化硅包覆的Eu(TTA)3phen在617.4 nm附近只是非常不明显的肩峰.这说明了二氧化硅包覆稀土配合物后,Eu(TTA)3phen的结构变得更加刚性化,从而使得荧光强度增强.荧光寿命实验结果表明二氧化硅包覆后的稀土配合物寿命减少,这正是由于稀土配合物分子结构刚性化造成的.     

铕与4-(4-吡啶甲酰基)苯甲酸配合物的合成与荧光性能研究

以Eu3+为中心离子,4-(4-吡啶甲酰基)苯甲酸(HPFBA)、1,10-菲罗啉(Phen)和三苯基氧膦(TPPO)为配体,合成了新型配合物Eu(PFBA)3(H2O)4,Eu(PFBA)3Phen(H2O)3和Eu(PFBA)3TPPO(H2O)3(PFBA=4-(4-吡啶甲酰基)苯甲酸根).红外光谱表明,形成配合...     

2-(4-氯代苯甲酰基)苯甲酸配合物光致发光研究

以Eu3+,Tb3+为中心离子,2-(4-氯代苯甲酰基)苯甲酸(HCBBA)为第一配体,邻菲咯啉(Phen)、三苯基氧膦(TPPO)、二苯亚砜(DPSO)为第二配体,合成了多种铕铽的二元和三元配合物,并测试其荧光效能,以研究配体的加入对中心离子发光强度的影响。结果表明,合成的配合物均发出Eu(Ⅲ)和Tb(Ⅲ)的特征荧光,但相对强度明显不同。在铕与2-(4-氯代苯甲酰基)苯甲酸根(CBBA)形成的配合物体系中,Phen和DPSO显示了较强的敏化作用,且Phen敏化效果更强,而TPPO则对配合物荧光有猝灭作用。在Tb-CBBA体系中,DPSO表现出很强的敏化作用, Phen和TPPO却对配合物荧光起猝灭作用,且TPPO猝灭效果更强。经红外推测,羧酸根均以双齿桥式与Eu3+和Tb3+配位;在3 200～3 600 cm-1出现水的弱的羟基的伸缩振动吸收峰,表明配合物中含有结晶水。     

三价铕荧光络合物与聚乙烯吡咯烷酮复合物研究

为研究稀土荧光络合物与高分子形成的复合物的结构与发光性能间的关系,利用α-噻吩甲酰三氟丙酮（TTA）和三苯基氧化膦（TPPO）与氯化铕（EuCl₃）分别制备了Eu(TTA)₃·2H₂O和Eu(TTA)₃·(TPPO)₂络合物,及其与聚乙烯吡咯烷酮（PVP）的复合物。采用荧光光谱,红外光谱和透射电镜等方法对复合物进行了表征。荧光光谱测定结果表明Eu(TTA)₃·2H₂O与PVP K30结构单元摩尔比为1∶35的PVP/Eu(TTA)₃·2H₂O复合物的612　nm发射峰的荧光强度较Eu(TTA)₃·2H₂O络合物有显著提高。红外光谱研究表明络合物的Eu3+与PVP分子的羰基之间存在着明显的配位作用,并且存在多种配位方式。透射电镜观察结果表明复合物具有微相分离结构,其中的稀土络合物为无定形结构,这进一步表明PVP与络合物分子间存在相互作用。