溶剂对若丹明6G荧光寿命的影响(英文)

采用时间相关单光子计数技术测量了若丹明6G在不同溶剂中的荧光寿命.实验结果表明:在若丹明6G浓度为10~(-4)克分子/立升条件下,它的荧光寿命和溶质分子生成氢键的能力呈线性函数关系.据此,并参照溶剂对若丹明6G吸收光谱影响的实验结果,可以认为,溶剂对若丹明6G荧光寿命的影响主要是通过在溶质和溶剂分子间生成氢键,从而影响了若丹明6G分子发生缔合的容易程度所致.     

胶束中的若丹明6G荧光增强和激光行为

使用阴离子表面活性剂十二烷基硫酸钠 (SDS)有效的增强了若丹明 6G染料水溶液的荧光 ,在若丹明 6G浓度分别为 5 47× 10 -7和 5 47× 10 -4 mol·L-1时 ,最大增强比率分别为 1 95和 9 7。在后一浓度下SDS的加入使若丹明 6G染料激光阈值降低 ,能量转化效率提高。不加SDS时的激光阈值功率密度约为 6 5MW·cm-2 ,加入 4 1× 10 -2 mol·L-1的SDS后 ,激光阈值功率密度降为 0 8MW·cm-2 。泵浦光功率密度为 6 5MW·cm-2 时 ,能量转化效率达到 2 5 %。同时还观察到SDS的加入使溶液吸收谱、荧光谱和染料激光发生了红移。对以上现象的物理机制进行了讨论。     

SiO2纳米颗粒对R6G-乙醇溶液荧光光谱影响

在3×10-4M和1×10-4M浓度的R6G-乙醇溶液中分别掺杂了8个不同浓度的SiO2纳米颗粒(107～1012个/mL).研究了SiO2纳米颗粒(100 nm)对若丹明6G(R6G)荧光光谱的影响,结果表明:n1～n4(1012～1010个/mL)浓度掺杂的SiO2纳米颗粒在549 nm处的有很好的荧光增强作用,对...     

十二烷基硫酸钠(SDS)增强若丹明6G水溶液激光激发荧光谱研究

报道了若丹明6G水溶液添加不同浓度的表面活性剂十二烷基硫酸钠(SDS)时激光激发染料的变化,发现较低的掺入量导致R6G荧光减弱,适量SDS的加入使荧光增强,在5×10-5 mol·L-1的R6G水溶液中,加入6×10-2 mol·L-1 SDS,荧光增强因子达到3.1。当R6G浓度为1×10-4 mol·L-1时,加入2×10-2 mol·L-1,染料激光阈值显著降低。测量了不同浓度的R6G溶液的吸收光谱及加入不同浓度SDS后的荧光谱,分析了不同SDS加入量下R6G荧光减弱及增强的物理机制。     

有机染料溶液中简并的四波混频和位相复共轭研究(英文)

研究了近共振增强的四能级系统有机染料溶液中简并的四波混频后向反射波及前向波的位相复共轭特性。用有效长度为5mm,浓度为2.5×10~(-5)mol的叶录素A甲醇溶液作介质,当调QNd:YAG倍频泵浦光的能量为8mj时,非线性反射率为22％。 对于若丹明6G酒精溶液,在相同条件下的反射率为10％。用象差板检证了位相复共轭特性。用调QNd:YAG激光辐射作泵浦源,研究了若丹明6G酒精溶液双光子共振增强的简并的四波混频作用。当介质浓度为10~(-4)克分子,有效长度为5mm,泵浦光能量为70mj时,非线性反射率达14％。测量了非线性反射率与介质浓度及入射物波与后向反射波的强度的关系曲线。理论分析了四波混频前向波的位相复共轭特性,用调QNd:YAG倍频激光作泵浦源,若丹明6G酒精溶液作介质,实验上证实了理论的预言。另外,把四重简并的四波混频推广到二重简并的情况。用若丹明6G酒精溶液作介质,实现了由6300A到5320A的象转换。用9740有机染料二氯乙烷饱和吸收溶液作介质,实现了1.06μm到5320A的象转换。当介质长度为5mm,泵浦光束的能量为5mj时,后者的转换效率为25％。理论分析表明,用对红外近共振吸收,而对可见辐射是透明的介质可以实现高效率的红外象转换。这种红外象转换的方法还具有实时、快响应等优点。     

若丹明6G和若丹明B混合染料荧光谱特性及染料激光行为

实验发现若丹明6G和若丹明B混合溶液的荧光谱峰值波长随两种物质的混合比例不同而有规律地变化,与单一的若丹明6G和若丹明B相比,混合溶液的荧光谱线宽度明显增宽。使用混合染料,用改变混合比的方法对染料激光进行调谐,可简化调谐方法,调谐范围为557.4-588.5nm。     

用四波混频产生高效率衍射极限输出的染料激光

本文提出采用共振增强四波混频的相反传播的泵浦光束泵浦若丹明6G酒精溶液,获得高效率衍射极限输出激光束的方法。使用KDP晶体调QNd:YAG振荡器和Nd:玻璃放大器激光系统,经KDP晶体倍频的5320埃激光作为泵浦光。浓度为5×10~(-5)克分子的若丹明6G酒精溶液作为染料激光器的激活介质,它同时作为四波混频的非线性介质。当泵浦功率密度为5×10~6瓦/厘米~2时,得到转换效率达50％以上,光束发散角为衍射极限。本文对这种新型染料激光器的高质量输出特性作了理论分析。     

多道检测-激光诱导荧光光谱分析装置研究

采用Nd∶YAG激光器为激发光源,与CCD光学多道分析系统联用建立了多 道检测-激光诱导荧光光谱分析装置,并对该装置的设计进行了优化,荧光光谱测量范围35 0～1 000 nm,波长精度0.3 nm,探测器光谱响应灵敏度0.1 LX。采集和检测了若丹明6G乙 醇溶液的高信噪比荧光谱,最低检出限达到10-8 mol/L。线性范围为10-6～10-8 mol/L。将所建立的装置用于若丹明B荧光淬灭法测定水中硒的含量,获得了满意 的结果。方法的线性范围为1～10 μg/L,检出限为0.5 μg/L,加标回收率为81.3%～112.5 %。     

SiO2纳米颗粒对R6G-乙醇溶液荧光光谱影响

在3×10－4M和1×10－4M浓度的R6G-乙醇溶液中分别掺杂了8个不同浓度的SiO2纳米颗粒（107～1012 个/mL）.研究了SiO2纳米颗粒（100 nm）对若丹明6G（R6G）荧光光谱的影响,结果表明:n1～n4(1012～1010个/mL)浓度掺杂的SiO2纳米颗粒在549 nm处的有很好的荧光增强作用,对570 nm处的荧光峰有明显的粹灭作用|n5～n8(109~107个/mL)浓度掺杂的SiO2纳米颗粒在549 nm处没有明显的荧光增强作用,但对570 nm处的荧光峰有增强作用,荧光增强因子可达10%~20%.荧光增强与粹灭的原因在于纳米颗粒对荧光的散射作用和R6G无荧光H-型二聚体或荧光J-型二聚体的形成.     

若丹明6G共振增强苯(C6H6)的受激拉曼散射实验研究

报道了若丹明6G乙醇溶液中苯的受激拉曼散射Stokes波共振放大的实验研究.在特定的染料溶液浓度下,1阶、2阶Stokes波得到有效放大,放大倍数分别为3.81和6.1.对荧光共振放大SRS的物理机制进行了分析讨论.     

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.     

外部荧光种子植入法增强液芯光纤中CS2的受激拉曼散射研究

本文报道了运用外部荧光种子(罗丹明6G乙醇溶液)植入法对液芯光纤中CS2受激拉曼散射的增强研究。实验结果表明, CS2的二阶、三阶Stokes波分别获得了1.92和11.71倍的增益。并对外部荧光种子植入法增强液芯光纤中受激拉曼散射的机制进行了分析。     

Au@SiO2 core/shell nanoparticle assemblage used for highly sensitive SERS‐based determination of glucose and uric acid

The use of Au@SiO₂ core/shell nanoparticle (NP) assemblage with highly sensitive surface‐enhanced Raman scattering (SERS) was investigated for the determination of glucose and uric acid in this study. Rhodamine 6G dye molecules were used to evaluate the SERS enhancement factor for the synthesized Au@SiO₂ core/shell NPs with various silica shell thicknesses. The enhancement of SERS signal from Rhodamine 6G was found to increase with a decrease in the shell thickness. The core/shell assemblage with silica layer of 1–2 nm over a Au NP of ~36 nm showed the highest SERS signal. Our results show that the SERS technique is able to detect glucose and uric acid within wide concentration ranges, i.e. 20 ng/dL to 20 mg/dL (10⁻¹²–10⁻³ M) and 16.8 ng/dL to 2.9 mg/dL (10⁻¹¹–1.72 × 10⁻⁴ M), respectively, with associated lower detection limits of ~20 ng/dL (~1.0 × 10⁻¹² M) and ~16.8 ng/dL (~1.0 × 10⁻¹¹ M). Our work offers a low‐cost route to the fabrication of agile sensing devices applicable to the monitoring of disease progression. Copyright © 2013 John Wiley & Sons, Ltd.     

Influence of temperature and ethanol content on aggregation of rhodamine 6G molecules in aqueous ethanol solutions

The effect of temperature on absorption spectra of Rhodamine 6G at concentrations of 10⁻⁶ and 10⁻³ M in water:ethanol solutions of various ethanol content was studied. The dimeric molecular fraction of Rhodamine 6G (10⁻³ M) was found as a function of temperature and ethanol content in the aqueous solution. It was shown that the absorption spectrum of Rhodamine 6G dimers (10⁻³ M) is dependent on temperature and ethanol content in the aqueous solution. Based on the relationship between J-and H-bands in the absorption spectrum of Rhodamine 6G dimers, both the angle between planes of associated Rhodamine 6G dye molecules and the free enthalpy of association were calculated. The structure of Rhodamine 6G dimers depends essentially on the ethanol content and aqueous ethanol solution temperature while experiencing the most temperature changes at an ethanol concentration of 25%. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 640–645, September–October, 2008.     

花状纳米金结构阵列的工艺制备与拉曼增强研究

基于纳米球光刻技术制备了一种花状纳米金结构阵列,经过PS509 nm球旋凃和ICP氧刻蚀,再通过镀金膜与高温退火工艺,纳米球阵列的表面被粗糙化,进而形成了一种鳞状的花状阵列 。FDTD仿真结果表明,制备的这种阵列具备很高的电磁场增强特性,主要的增强集中于纳间隙的边缘处。以罗丹明 6G染料为探针分子测试基底的拉曼效应,与金基底的拉曼信号相比,该纳米结构阵列拉曼增强效应明显,对罗丹明 6G的检测极限达到了10-6 mol/L的水平。     

花状纳米金结构阵列的工艺制备与拉曼增强研究

基于纳米球光刻技术制备了一种花状纳米金结构阵列,经过PS509 nm球旋凃和ICP氧刻蚀,再通过镀金膜与高温退火工艺,纳米球阵列的表面被粗糙化,进而形成了一种鳞状的花状阵列 。FDTD仿真结果表明,制备的这种阵列具备很高的电磁场增强特性,主要的增强集中于纳间隙的边缘处。以罗丹明 6G染料为探针分子测试基底的拉曼效应,与金基底的拉曼信号相比,该纳米结构阵列拉曼增强效应明显,对罗丹明 6G的检测极限达到了10-6 mol/L的水平。     

Spectral-Kinetic Properties of Laser Dyes in Active Elements on the Basis of Sol-Gel Matrices

The absorption and photoluminescence spectra as well as the photoluminescence lifetimes of laser dyes (Phenylamine 430, Rhodamine 6G, Rhodamine 6G zwitterion, Rhodamine 4C, and Rhodamine 101) in new matrices are studied. These matrices represent the hybrid of two types of porous glasses (microporous and sol-gel glass). Chemical transformations of the dye molecules in the matrices are not found. The dye dimers mentioned above are also absent for concentrations up to 10^-4 M. The luminescence efficiencies of the dyes in the matrix and in the ethanol solutions are compared. The difference in concentration dependences of the photoluminescence spectrum of Rhodamine 6G in the matrix and ethanol solution is found and discussed. The collective emission of the dyes in new matrices is observed at a power density of exciting radiation of 10²⁵ cm^-2s^-1 and a concentration of 10^-4 M. The energies and collective emission spectra of the dyes in the matrix are compared with those in the solutions.     

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。