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罗丹明B荧光增强苯受激拉曼散射研究 总被引:1,自引:1,他引:0
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。 相似文献
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Kieu K Schneebeli L Merzlyak E Hales JM DeSimone A Perry JW Norwood RA Peyghambarian N 《Optics letters》2012,37(5):942-944
We report on a new platform for all-optical switching based on inverse Raman scattering in liquids. Narrowband switching, which could be suitable for wavelength-division-multiplexed applications, is demonstrated using integrated liquid-core optical fiber infiltrated with both neat liquids (CCl(4) and CS(2)) as well as an organic chromophore (β-carotene) dissolved in CCl(4). Compared to standard glass optical fibers, these liquids have much larger Raman loss coefficients, which help reduce the pump power by at least an order of magnitude. Further improvements can be expected with the development of highly soluble organic compounds possessing large Raman cross sections. 相似文献
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四氯化碳萃取辅助的水中甲烷拉曼探测技术研究 总被引:1,自引:0,他引:1
在常温常压下,由于甲烷(CH4)在水中的溶解度很低,使用常规拉曼光谱技术很难获得水中溶解的低浓度甲烷的拉曼信号。为解决上述问题,提出了一种四氯化碳(CCl4)萃取辅助的探测新方法。利用萃取作用,把溶解在水中的微量甲烷富集到四氯化碳溶液中,通过对其中溶解的CH4拉曼信号的探测以检验水中微量CH4的存在,以此提高实验室条件下水中溶解甲烷的探测灵敏度。在实验室条件(25℃,1atm)下,分别对CH4的饱和水溶液(浓度约为1.14mmol·L-1)、CCl4萃取液以及CH4的饱和CCl4溶液进行了光谱探测分析。结果表明,对CH4的饱和水溶液直接探测,未能获得CH4的拉曼信号;通过萃取辅助,成功地在CCl4萃取液中检测到CH4的拉曼信号,其强度与CH4的饱和CCl4溶液的信号强度相近,实现了在实验室条件下对水中溶存甲烷气体的探测。 相似文献
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液芯光纤可以使拉曼光谱强度提高103倍。研究了在stokes/anti stokes拉曼光谱强度比测温中如何获得理想测温结果的方法。用长为5.20m、内径为50μm的含C6H6和CCl4混合液体的液芯光纤,获得了高强度CCl4的±218cm-1,±314cm-1和±459cm-1的拉曼光谱。利用各光谱带的stokes与anti stokes的强度比(Is/Ia),确定了液芯光纤所在处的温度。实验结果表明,±459cm-1的强度比的实验值与理论值符合得很好,±218cm-1为较好,±314cm-1稍差一些。从理论和实验两方面总结了拉曼频移、光纤损耗、溶剂效应、仪器响应等对测温结果的影响。 相似文献
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在液芯光纤内产生共振拉曼效应,拉曼光谱强度可以提高10^9倍,样品吸收峰及浓度都影响拉曼光谱强度。样品浓度决定光纤的最佳长度。 相似文献
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Intensification of oxidation capacity using chloroalkanes as additives in hydrodynamic and acoustic cavitation reactors 总被引:1,自引:0,他引:1
Chakinala AG Gogate PR Chand R Bremner DH Molina R Burgess AE 《Ultrasonics sonochemistry》2008,15(3):164-170
The effect of the presence and absence of the chloroalkanes, dichloromethane (CH(2)Cl(2)), chloroform (CHCl(3)) and carbon tetrachloride (CCl(4)) on the extent of oxidation of aqueous I(-) to I(3)(-) has been investigated in (a) a liquid whistle reactor (LWR) generating hydrodynamic cavitation and (b) an ultrasonic probe, which produces acoustic cavitation. The aim has been to examine the intensification achieved in the extent of oxidation due to the generation of additional free radicals/oxidants in the reactor as a result of the presence of chloroalkanes. It has been observed that the extent of increase in the oxidation reaction is strongly dependent on the applied pressure in the case of the LWR. Also, higher volumes of the chloroalkanes favour the intensification and the order of effectiveness is CCl(4)>CHCl(3)>CH(2)Cl(2). However, the results with the ultrasonic probe suggest that an optimum concentration of CH(2)Cl(2) or CHCl(3) exists beyond which there is little increase in the extent of observed intensification. For CCl(4), however, no such optimum concentration was observed and the extent of increase in the rates of oxidation reaction rose with the amount of CCl(4) added. Stage wise addition of the chloroalkanes was found to give marginally better results in the case of the ultrasonic probe as compared to bulk addition at the start of the run. Although CCl(4) is the most effective, its toxicity and carcinogenicity may mean that CH(2)Cl(2) and CHCl(3) offer a safer viable alternative and the present work should be useful in establishing the amount of chloroalkanes required for obtaining a suitable degree of intensification. 相似文献
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本文以乙醇-甲酰胺,乙腈-甲酰胺,乙醇-环己酮,乙腈-环己酮四种混合溶液为研究对象,采用激光拉曼光谱对四种溶液体系的闪点行为进行讨论和研究。通过测定四种溶液体系的拉曼光谱和闪点,结合溶液拉曼光谱的特征峰强度比和拉曼位移的变化,探索四种溶液闪点的变化规律。试验结果表明,随着溶液浓度的增大,溶质的拉曼特征峰强线性增加,混合溶液的闪点降低。采用三次多项式分别对四种溶液体系的闪点与拉曼特征峰、溶液浓度的关系进行拟合,拟合结果良好。混合溶液的闪点随拉曼特征峰强比、溶液浓度的变化趋势相同。该试验方法将有助于从分子结构角度分析混合溶液的闪点变化规律,同时该方法可用于混合溶液闪点的实时在线检测。 相似文献
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拉曼光谱是研究水中生物分子重要的有效方法之一,然而由于拉曼散射截面小,特别是水分子的电子激发态能级高,因此水中生物分子的拉曼光谱测量甚为困难。将液芯光纤技术和共振拉曼技术结合起来,可大幅度提高拉曼光谱强度。实验中用可以获得最大的共振拉曼光谱强度的514.5 nm Ar+离子激光激发,分别用石英和Teflon液芯光纤对水中β-胡萝卜素生物分子进行了痕量检测研究。结果表明应用石英液芯光纤和Teflon液芯光纤可分别检测浓度为10-7~10-9mol·L-1和10-9~10-10mol·L-1的β-胡萝卜素。 相似文献
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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. 相似文献
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分别测量了CCl4和C6H6二元溶液和纯液体在不同压强下(0~11GPa)的拉曼光谱。结果表明二元溶液的压强效应明显不同于纯液体的压强效应:2种液体混合,由于体密度增加,分子间距离减小,分子间相互作用能增加,拉曼光谱线频移(兰移)速度增大,二元溶液频移速度大于纯液体的频移速度;谱线劈裂(相变)提前和固有频差Δ0随压强增加而加大;苯的ν1+ν6~ν8、四氯化碳的ν1+ν4~ν3费米共振消失压强减小;不同压缩系数的分子频移速度不同,密度较小的CCl4分子,化学键长,力常数小,压缩系数大,容易压缩。密度大的C6H6分子,化学键短,力常数大,压缩系数小,不易压缩。CCl4分子大多拉曼频移速度大于C6H6分子相近频率的频移速度。并对高压下分子谱线归属、认证有参考价值,对不同环境下的高压效应、分子间相互作用、溶剂效应等研究提供了方法和思路。 相似文献
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J. Zuo Y.-J. Tian J. Chen Y.-C. Wang S.-Q. Gao G.-H. Lu Z.-W. Li 《Applied physics. B, Lasers and optics》2008,91(3-4):467-473
We demonstrate stimulated Raman Stokes (SRS) scattering of carbon disulfide (CS2) influenced by a natural dye named all-trans-β-carotene in a liquid-core optical fiber (LCOF). These Stokes emissions can acquire the extra effects of seeding or suppression, both of which result from the optical properties of the carotenoids. Then, the efficient control of the selective developments of the Stokes lines by the natural dyes is available in LCOFs. Especially, the low threshold of the high-order Stokes lines, such as the 2nd Stokes line of CS2, can be more easily obtained through the seeding effect. The saturation intensity of the 1st Stokes line can be suppressed more when the concentration of all-trans-β-carotene in CS2 becomes high. Simultaneously, the threshold of the 1st Stokes line increases with the addition of the carotenoids. This result is expected to be worthy of new SRS-based fiber light sources for bio-medicine applications such as photodynamic therapy. 相似文献
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利用液芯光纤技术研究了不同浓度的β-Carotene的CS2溶液的吸收与荧光的特性对CS2的一、二阶Stokes谱线阈值的影响.实验发现随溶液浓度(10-8—10-6 mol/L)增加,CS2的一阶Stokes谱线的激发阈值相对变高;并且与纯CS2芯液的受激拉曼散射相比较,在低抽运能量激发下,就观察到CS2的二阶Stokes谱线.这主要是由于在CS2的受激拉曼谱线产生的过程中,β-Carotene的CS2溶液的吸收和荧光共同影响了CS2的一、二阶Stokes谱线的阈值.我们进行了理论上的拟合与分析,其结果与实验符合很好.
关键词:
2受激拉曼散射阈值')" href="#">CS2受激拉曼散射阈值
液芯光纤
吸收与荧光 相似文献
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报道了在液芯光纤内利用四磺酸基苯基卟啉荧光增强苯的高阶受激拉曼散射实验研究. 实验表明:利用荧光效应显著增强苯的高阶受激拉曼谱线的强度;高阶Stokes谱线的阈值明显降低;随着Stokes谱线阶数的增加,Stokes谱线宽度变窄. 用3.55 mJ小能量激光实现了液芯光纤内生物分子荧光增强受激拉曼散射. 此技术对实现宽带受激辐射、种子激光、生物大分子结构研究和生物分子的非生物利用等领域有广阔的应用前景.
关键词:
受激拉曼散射
荧光
液芯光纤 相似文献
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HASI Wuliji 《中国科学G辑(英文版)》2007,50(2):144-151
In this paper,a method of choosing mixture medium in two-cell stimulated Brillouinscattering(SBS)system to improve the system performance is proposed.The Brillouin frequency shift(BFS)of mixture medium varies with the mixing ratio andthus the difference of the BFS between the two cells can be eliminated.The two-cellSBS system with acetone(C3H6O)in its generator cell and mixture liquid ofCCl4/C2Cl4 in its amplifier cell is investigated.The C3H6O has a high optical breakdown threshold and the mixture liquid of CCl4/C2Cl4 has a small absorption coeffi-cient and the same BFS as that of C3H6O when the volume fraction of CCl4 is 4%.Compared with two-cell SBS system with the same liquid(C2Cl4)or different liquid(C3H6O and C2Cl4)in generator and amplifier cell,the SBS system with mixture liq-uid(CCl4/C2Cl4)in amplifier cell and C3H6O in generator cell improves thepower-load,energy reflectivity(ER),phase conjugation(PC)fidelity and ER stabil-ity. 相似文献