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王华馥 《物理》1991,20(8):455-460
本文介绍了近两年来我国在用拉曼散射和布里渊散时研究介电晶体、半导体、金属及半导体超晶格、高温超导体和磁性物质等方面的进展,以及表面增强拉曼和受激光散射研究的情况.  相似文献   

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紫外拉曼散射及其应用   总被引:1,自引:0,他引:1  
许存义  左健 《物理》1999,28(4):206-210
介绍了紫外拉曼散射,尤其是紫外共振拉曼散射的突出优点,并举例说明了该项技术在生物大分子结构研究、环境痕量污染物(如多环芳香碳氢化合物)的检测和CVD金刚石薄膜质量鉴定中的应用。  相似文献   

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刘战存  李慧鹏 《物理》2003,32(6):410-414
介绍了拉曼的生平和对物理学的主要贡献,回顾了他从观察海水的蓝色人手,继而发现气体、液体对光的散射规律,一直到发现物质的散射光不仅包含原来的波长,而且还包括与原入射光不同的其他波长的散射的研究过程,并讨论了他的成功对我们的启示.  相似文献   

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在本文中我们首次报道了p型掺杂的自组织Si/Ge量子点中空穴能级子带间的电子拉曼散射,此电子跃迁的能量为105meV。Si/Ge量子点Ge Ge模的共振拉曼散射表明此空穴能级间的电子拉曼散射与Γ点附近的E0(≈2.52eV)发生了共振,而E1的能量小于2.3eV.变温实验和偏振实验进一步证实了我们的指认。所有观测的实验数据与6 bandk·p能带结构理论的计算结果吻合得很好。  相似文献   

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研究了拉曼放大器中放大的自发拉曼散射对拉曼开-关增益的影响,并提出了一种利用自发拉曼散射谱来调整拉曼放大器位曼开-关增益平坦的方法,实验采用4个波长为14xx nm的激光二极管作为抽运源,75km的G.652光纤作为传输介质,获得了C波段附近的光放大,同时对此给出了合理的理论解释。  相似文献   

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相方相BaTiO3及BaTiO3:Ge的拉曼散射特性研究   总被引:1,自引:1,他引:0  
本文报道了在室温下BaTiOe及TiO3:Ce的拉曼谱的特点,着重讨论了前向散射配置下两个A1(TO)模(位于275cm^-1和516cm^-1左右)出现在A1(TO)谱中的原因,通过设计特别的前向散射实验得到了此配置下由于晶体出射两对入射光的反射造成的背向散射的强度。在BaTiO3的前向散射谱中扣除了背向散射面对人入射光的反射造成的背向散射的强度。在BaTiO3的前向散射谱中扣除了背向散射信号后  相似文献   

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 1921 年,印度物理学家拉曼(C. V. Raman)从英国搭船回国,在途中他思考着为什么海洋会是蓝色的问题,而开始了这方面的研究,促成他于1928 年2 月发现了新的散射效应,就是现在所知的拉曼效应,在物理和化学方面都很重要。  相似文献   

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多壁碳纳米管的拉曼散射   总被引:4,自引:1,他引:3  
本文报导了用直流碳弧放电方法制备的多层碳纳米管的拉曼光谱。和HOPG相比,由于碳纳米管的量子尺寸效应和碳纳米管直径的分布,在纯化和未纯化的碳纳米管中均存在E2g模的软化,其红移范围分布在2~13cm 1范围内。  相似文献   

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拉曼光谱技术作为探究分子、晶体及其结构特征的有力手段,具有快速、无损、样品用量小、无需前处理且适应性强等优点,已被广泛应用于食品安全、石油化工等领域。但在拉曼光谱应用中,常常受到荧光背景干扰,导致拉曼信号降低,严重的情况下拉曼信号甚至会淹没在荧光背景中。为解决拉曼技术在实际应用中荧光背景干扰的问题,从仪器角度出发,采用二色镜对多波长拉曼光谱进行光路耦合设计,研制了近红外拉曼光谱与移频差分拉曼复合一体的多波长消荧光拉曼光谱检测系统,其中近红外拉曼光谱采用1 064 nm激光光源设计,移频差分拉曼光谱选取784.5和785.5 nm两组激光光源进行时分复用,在移频差分拉曼光谱检测的同时,亦可获得两组单波长拉曼光谱数据。通过对比同步测试和分时逐次测试的强度及峰位稳定性,验证了多波长消荧光拉曼光谱仪的同步测试性能;选取了多种荧光背景强弱不同的样品,进行了单波长拉曼、近红外拉曼及移频差分拉曼光谱的对比分析。针对丙酮、乙腈等荧光背景较弱的样品,可采用单波长拉曼光谱对样品进行定量及定性分析;针对食用油、红色塑胶微粒等荧光背景与拉曼信号强度相当的样品,可采用近红外拉曼光谱对样品进行定量及定性分析;针对红酒、棕色塑胶微粒等荧光背景较强的样品,需结合近红外拉曼光谱和差分拉曼光谱对样品进行定性分析。研究表明:通过多波长消荧光拉曼光谱检测系统的研制,在常规单波长拉曼光谱技术的基础上,将两种抑制荧光干扰技术有机结合,有效扩充了应用领域及样品检测范围。  相似文献   

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A scanning standoff Raman spectroscopy system has been developed to measure the molecular species of distant samples in two dimensions. Computer software is used to control the scanner pan and tilt angles, and Raman measurements are collected of the distant sample area in an xy grid pattern. The Raman spectra at each grid point are measured and processed to obtain an image of the distant surface composition. The ability to provide interpolated images of distant molecular species is illustrated. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

13.
拉曼光谱技术的应用及研究进展   总被引:21,自引:6,他引:15  
本文简述了拉曼光谱产生的机理以及与红外光谱的区别,讨论了拉曼光谱在聚合物、生物分子、蛋白质和无机物等方面研究及应用,介绍了傅立叶变换拉曼、共焦显微拉曼、表面增强激光拉曼、固体光声拉曼光谱的原理及其应用以及拉曼光谱和其他检测手段的联用技术。  相似文献   

14.
复合输出镜(Nd,Ce):YAG拉曼频移激光器研究   总被引:2,自引:2,他引:0  
钟呜  韩凯 《光学学报》1995,15(4):09-512
报道了由部分反射凹面镜和辅助平面镜构成的复合输出镜高压CH4气体(Nd,Ce):YAG拉曼频移激光器的理论和实验研究结果,在10J的输入下,获得12mJ的拉曼激光输出,并计算的基频场基模光束参数。  相似文献   

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拉曼光谱技术在爆炸物检测中的应用   总被引:1,自引:0,他引:1  
姜杰  李明  张静  高静 《光散射学报》2013,25(4):367-374
随着恐怖活动的蔓延,对爆炸物的检测和溯源变得越来越重要。拉曼光谱能够提供化合物的指纹图谱,是对物质定性分析的有力工具,具有无损、快速、准确度高等优点,近年来在爆炸物检测领域被广泛应用。本文介绍了共聚焦显微拉曼光谱、空间偏移拉曼光谱、表面增强拉曼光谱等拉曼光谱技术在爆炸物检测方面的应用及最新研究进展。  相似文献   

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Raman optical activity (ROA) has been exclusively observed in the visible (VIS) and near‐infrared (NIR) spectral regions to date. During the last few years, we have designed, constructed and tested the first ROA instrument, operating in the deep‐ultraviolet (DUV) spectral region employing 244‐nm excitation. This novel DUV ROA instrument is based on a backscattering geometry and incident circular polarization modulation (ICP); it makes use of a fast DUV imaging lens‐based spectrograph and specially designed DUV grade polarization optics. The performance of this instrument has been evaluated by analysing measured non‐resonant DUV ROA spectra of non‐absorbing enantiomeric liquid samples and by comparing these with corresponding ROA spectra recorded in the visible spectral region. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

17.
高压下NaCl水溶液的Raman光谱不连续性的证据   总被引:1,自引:0,他引:1  
在温度21 ℃和压力50~1 100 MPa范围内利用碳化硅压腔进行了10%的NaCl水溶液的Raman光谱的原位测量和研究。研究发现:溶液的Raman拟合谱峰在50~300 MPa压力范围内,随着压力的增加向低波数方向移动,在约300 MPa时达到最小值;在300~800 MPa压力范围内,压力的升高则导致谱峰向高波数方向移动,在约800 MPa时达到最大值;随着压力的进一步升高(>800 MPa),谱峰又向低波数方向移动。类似地,拟合谱峰的峰面积比值和半高宽在压力约300和800 MPa时也发现了不连续现象。这表明高压下NaCl水溶液的内部结构是不连续的,溶液中的氢键(O—H…Cl-)发生了相应的变化,意味着溶液中出现了结构的重新排列,产生了较为复杂的结构构型。  相似文献   

18.
In this study we report the first observation of spontaneous Raman solitons in stimulated Raman scattering (SRS) by the gas NH3. The scattered radiation is called Stokes radiation. Raman solitons are of considerable interest, because their existence can be explained by quantum-mechanical fluctuations of the electromagnetic field in vacuum. We have observed spontaneous Raman solitons in a forward SRS configuration for two different molecular transitions of NH3, the laser emissions at 58 μm and 72.6 μm wavelength. These are optically pumped by 10 μm CO2-laser pulses with a duration of 100 ns and an energy of 150 mJ. Spontaneous Raman solitons are short spikes in the pump pulse which occur during its depletion. Their origin is the rapid π phase change of the Stokes seed. In contrast to other laboratories we have used single-pass cells. Thus, we have succeeded in observing multiple spontaneous Raman solitons during one pump pulse. Previous experiments with multi-pass cells never showed multiple solitons. Since multiple spontaneous Raman solitons have already been reported in an earlier experiment with a single-pass cell filled with hydrogen at high pressure, we conclude that such multiple Raman solitons can be observed mainly in this type of gas cell. Subsequently, we have performed statistical measurements on the delay time and the height of the spontaneous Raman solitons in the depleted pump pulse for the 58 μm-NH3 emission. We have compared these statistics with theory and equivalent experimental results of other laboratories. They are in good agreement with the assumption that quantum-mechanical fluctuations are the origin of spontaneous Raman solitons. The most recent theories postulate that the origin of the formation of spontaneous Raman solitons can be explained by the rapid π phase change of the Stokes seed as well as that of the laser or polarization wave. Therefore, we have determined the phase of the spontaneous Raman solitons relative to the depleted pump pulse. Although, such changes of sign of the relative phase have already been observed in an earlier SRS experiment with hydrogen at high pressure, we did not detect any in our experiment. Therefore, we conclude that in this experiment the π phase change occurs in the Stokes or polarization wave.  相似文献   

19.
The development of devices to detect explosive substances in situ with characteristics such as easy portability, simple operation, and quick response is of high interest nowadays. Raman spectroscopy meets most of these requirements, allowing for the identification of volume and trace amounts of an unknown substance. In this paper we report the characterization of explosive substances such as ANFO and pentolite, both in their pure forms as well as mixed with other substances, such as sugar and sodium hydrogen carbonate, using a portable Raman Enwave Optronics EZRaman-model M, whose signal is sent and received by a head coupled to an optical fiber. The obtained spectra have been validated by comparison with those obtained by a conventional Raman spectrometer with high resolution. We discuss the advantage of using miniaturized laptops running with a 785-nm laser, making a correction of the signal response to obtain optimized spectral fingerprints with minimum noise, in order to design an autocalibrated, easily portable device that performs the function of identification of the mentioned substances.  相似文献   

20.
青霉素类药物拉曼散射的研究   总被引:5,自引:1,他引:4  
利用显微拉曼技术对三种常见青霉素类药物做了测试和分析,得到拉曼散射谱。发现不同类青霉素的拉曼谱线有明显区别,可以用以鉴别药物。文章还给出了青霉素药物的特征峰以利区别。  相似文献   

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