Study of photochemical fluorescence enhancement of the terbium-lomefloxacin complex

Lomefloxacin (LMFX) and terbium ion can form a complex and the sensitized fluorescence of the terbium ion can be observed. It was found that the sensitized fluorescence intensity can be notably enhanced when the terbium complex is exposed to 365 nm ultraviolet light. By the fluorescence spectra, phosphorescence spectra, fluorescence quantum yield and fluorescence lifetime of the system, it was proved that irradiation of the complex made it undergo a photochemical reaction and a new terbium complex which is more favorable to intramolecular energy transfer was formed. This is why the sensitized fluorescence enhancement can be observed. (C) 1999 Elsevier Science S.A. All rights reserved.

Fabrication and fluorescence study of sensitizing dye TiO2 films

Fluorescence spectra of the sensitizing dye/TiO2 bilayer films were studied. Charge-transfer complexes were formed in the above bilayer.

The suppression of Ge-132 on the Maillard reaction of BSA by fluorescence spectrum

The fluorescences of BSA and glycosylated BSA were observed respectively. The lambda(cm) of BSA was 340 nm; while the lambda(cm) of glycosylated BSA was 436 nm. Because the fluorescence spectra of them were different greatly, we can observe the suppression of Ge-132 on the Maillard reaction of BSA without any interference of itself. It was showed that the fluorescence intensity of glycosylated BSA increased continuously with the cultured time, Ge-132 may suppress the Maillard reaction of BSA greatly, and the suppressing efficicency would be 32 %. The key site of the Maillard reaction of BSA is free amino groups of alanine residues on N-terminal amino group, besides the epsilon-amino groups of intrachain Lysine residues.

STUDY ON RARE EARTH-HEDTA-SERINE TERNARY SYSTEM BY POTENTIOMETRY AND FLUORESCENCE SPECTROSCOPY

In this pare earth-HEDTA-serine (Ser) ternary system has been studied by potentiometric titration at 25 degrees C with an ionic strength of 0.15 mol.L-1 (NaCl). The excitation and fluorescence spectra of TbCl3, Tb-Ser, Tb-HEDTA and Tb-HEDTA-Ser have hem determined at room temperature. The stability constants of these ternary complexes have been obtained, It lieu been found that Tb-HEDTA-Ser ternary system exhibit characteriatic fluorescence spectrum of Tb3+ sensitized by two ligands,The results mean that the chemical hood between the control ion and the ligand in this ternary system is predominantly ionic in character,and the energy transfer from ligand to Tb8+ is performed by a kind of abort-range electron exchange action.

FLUORESCENCE SPECTROSCOPIC STUDIES ON THE DYE MIXTURE SYSTEM C440/C540/Saf.-T

The fluorescence spectra and lifetimes of the ternary due mixture C440/C540/Saf. -T were studies. Experimental results indicated that there are efficient energy transfer among these three components of the dye system. Consequently this system may he expected to be a potemtial eandidate of laser dye giving out output in three different wavelength regions. From. the relation of donor fluorescence lifetime as a function of aceeptor concentration and the relation of accepter fluorescence intensity as a funotion...

Micromodification of element distribution in glass using femtosecond laser irradiation

We report micromodification of Eu element distribution in a silicate glass with femtosecond laser irradiation. Elemental analysis shows that the content of Eu decreased at the focal point and increased in a ring-shaped region around the focal point, which indicates migration of Eu ions has been induced by the femtosecond laser irradiation. Confocal fluorescence spectra demonstrate that the fluorescence intensity of Eu3+ ions increased by 20% in the laser-induced, Eu-enriched, ring-shaped region compared with that for nonirradiated glass. The mechanism for the laser induced change in fluorescence properties of Eu3+ has been investigated. (C) 2009 Optical Society of America

Multiphoton-excited upconversion luminescence of Nd : YVO4

Fluorescence spectra of Nd: YVO4 under excitation of a continuous wave (CW) diode laser and a femtosecond laser at 800nm were investigated. It was found that Nd: YVO4 shows different upconversion and downconversion luminescencent behaviors when excited by the diode laser and the femtosecond laser. The dependence of the upconversion luminescence intensity on the pump power of the femtosecond laser was discussed. The populations of the upper energy levels for upconversion and downconversion luminescence were calculated based on the Bloch equations. The calculations agree well with the experimental results. (c) 2007 Optical Society of America.

两种新型芴类衍生物的三光子吸收特性研究

研究了两种新型芴类衍生物9，9-二(2-乙基已基)-2，7-二咔唑-9H-芴(简记为DCZF)和9，9-二(2-乙基已基)-2，7-二(2-(4-甲氧基)苯-2，1-乙烯基)芴(简记为BMOSF)在N，N-二甲基甲酰胺(DMF)中的线性吸收和单光子荧光行为，并用脉冲宽度为38ps，重复频率为10Hz的1064 nm Nd：YAG脉冲激光研究了两种化合物的三光子吸收性质．结果表明：两种新材料的最大线性吸收峰分别位于330和380nm，吸收区域覆盖了270-420nm波段．两种化合物的荧光带位于蓝-紫区，中心

铒离子浓度对掺Er^3＋碲酸盐玻璃的Judd-Ofelt理论参数的影响

制备了四种不同铒离子掺杂浓度的碲酸盐玻璃，通过测定吸收光谱计算了吸收谱线的振子强度，根据Judd-Ofelt理论计算了不同浓度下Er^3＋离子发光光谱的强度参数Ω（i=2，4，6），计算了自发辐射电偶和磁偶跃迁概率、辐射寿命、荧光分支比等参数，讨论了Er^3＋离子浓度变化对以上这些参数的影响。测试了Er^3＋：^4I13／2→^4I15／2跃迁对应的荧光光谱和Er^3＋：^4I13／2能级荧光寿命。最后应用McCumber理论计算了玻璃中Er^3＋：^4I13／2→^4I15／2跃迁对应的受激发射截面大小

Spectroscopic properties of Er3+/Yb3+ codoped fluorophosphate glasses

Er3+/Yb3+ cocloped fluorophosphate glasses were prepared and their thermal stabilities, Raman spectra, absorption spectra, and fluorescence spectra were measured. It is found that proper content of NaF or PbF2 is helpful for the increase of stability against crystallization. The variation of AI(PO3)3 or NaF content in the composition affects not the maximum phonon energy but the phonon density. The introduction of PbF2 decreases the phonon energy slightly. Intense green and red upconversion luminescence was observed for the fluorophosphate glass with low phosphate content. A glass matrix for upconversion luminescence requiring neither expensive raw material nor special atmospheric conditioned preparation is provided. Infrared luminescence around 1530 nm was researched. Fluorophosphate glasses with bandwidth properties and stimulated-emission cross sections better than tellurite, germanate and silicate glasses are obtained. Through the introduction of NaF, the bandwidth properties are decreased. Through the introduction of PbF2 the gain properties are increased. On the whole, it is difficult to obtain a material with the best gain properties and bandwidth properties simultaneously. There should be a compromise between them according to the demand. (C) 2006 Elsevier B.V. All rights reserved.

钕离子掺杂和钕铝共掺高硅氧玻璃的光谱性质研究

Nd-doped and Nd-Al-codoped high silica glasses were obtained by sintering porous glass impregnated with Nd3+ and Al3+ ions. The absorption, fluorescence spectra and fluorescence lifetime of Nd-doped and Nd-Al-codoped high silica glasses were measured. The intensity parameters Omega(1), ( t = 2, 4, 6), fluorescence lifetime, radiative quantum efficiency and stimulated emission cross section were calculated by Judd-Ofelt theory. The effect of aluminum codoping on the fluorescence and structural properties of Nd-doped silica glass has been discussed. By comparing the spectroscopic properties with other Nd-doped oxide glasses and commercial silicate glasses, this Nd-doped high silica glass is likely to be a promising laser material for use in high power and high repetition rate lasers.

不同玻璃组分对掺铒碲酸盐玻璃 光谱性质的影响

Series of tellurite glasses were prepared by traditional melting method, the glass composition were changed and the different effects of glass modifier oxides(alkali metals and alkaline earth metal oxides) and glass intermediate (Y2O3, GeO2, Nb2O5, WO3) on the optical and spectroscopic properties of Er³⁺ doped tellurite glass were researched and compared. The infrared transmitting spectra, absorption spectra and fluorescence spectra were tested, the results showed that Nb2O5 and WO3 in the glass act as part of the body's role in the formation of the network, caused the reduction of transmitting range in infrared wavelength, which decrease the transmitting properties of tellurite glass. The introduction of high valence cationic ions, WO3 especially, can increase the FWHM of Er³⁺ for the increased polarization effect. With the decreasing of cationic field of glass modifier ions, the ion filed of the environment around Er³⁺ increased, subsequently, the role of ligand field polarization effect reduced, which makes the luminescence lifetime increase, and on the contrary the FWHM decrease monotonously.

Optical transitions and upconversion luminescence of Er3+/Yb3+-codoped halide modified tellurite glasses

Er3+-doped halide modified tellurite glasses were synthesized by conventional melting and quenching method. The Judd-Ofelt analysis was performed on the absorption spectra and the transition probabilities, excited state lifetimes, and the branching ratios were calculated and discussed. The intense infrared and visible fluorescence spectra under 980 nm excitation were obtained. Strong upconversion signal was observed at pumping power as low as 30 mW in the glasses with halide ions. The upconversion mechanisms and power dependent intensities were discussed, which showed two-photon process are involved for the green and red emissions. The decay times of the emitting states and the corresponding quantum efficiency were determined and explained. (C) 2004 American Institute of Physics.

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.

Study of hybrid TiO2/ormosil films doped with laser dyes

TiO2/ormosil films doped with laser dyes have been prepared by the sol-gel method. Spectroscopic properties of the entrapped dyes are studied by the absorption and emission techniques. The results indicate that the absorption and fluorescence spectra of kiton red depend strongly on the properties of the ormosil matrices. The heat-treatment of the kiton red-doped film obviously leads to the increasing fluorescence intensity and the largest fluorescence intensity is obtained after heat-treatment of 150 degrees C for 2 h. However, the fluorescence intensity of the rhodamine 6G-doped film decreases with the increase of the heat-treatment temperature. (c) 2005 Elsevier B.V. All rights reserved.