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相干反斯托克斯喇曼散射是一种比自发喇曼散射转换效率高得多的非线性过程。由于可调谐染料激光器日趋成熟及商品化,使相干反斯托克斯喇曼光谱(CARS)近几年来在国外得到颇为迅速的发展,成为一种具有高光谱分辨率和高空间分辨率的新颖光谱技术,引起人们广泛的兴趣。 相似文献
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相干反斯托克斯喇曼光谱学(CARS)是光谱学的一门新的重要分支,也是激光光谱学的一个重要领域。由于它具有独特性质而成为一个强有力的分析工具,所以引起人们越来越大的注意。我们建成了一套以重复脉冲 YAG:Nd~(3+)激光器作为光源的完整的 CARS 实验装置,并且获得相干反斯托克斯拉曼散射(CARS)和相干斯托克斯喇曼散射(CSRS)。该装置由以下五部分组成: 相似文献
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本文使用染料测Q红宝石激光激励液氮的受激喇曼散射,观察到一级斯托克斯、一级反斯托克斯和二级反斯托克斯线,测得散射光的喇曼频移、线宽、能量转换率和退偏振度等参数.并对所得结果进行了讨论。 相似文献
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Coherent anti-Stokes Raman scattering spectroscopy(CARS) is a well-known detecting tool in biosensing and nonlinear spectroscopy. It can provide a non-invasive alternative without the need for exogenous labels, while the enhancement factor for surface plasmon resonances(SPR) are extensively used to increase the local field close to the oscillators and which can obtain high enhancement. In this work, we investigate the enhancement factor of our structure for surface-enhanced coherent anti-Stokes Raman scattering. The absorption spectrum of the structure has been studied, a wide range of absorption has been realized. The enhancement can be as high as 1016 over standard CARS. Our design is very useful for improving the enhancement factor of surface-enhanced coherent anti-Stokes Raman scattering. 相似文献
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Fano共振效应拥有独特的局域场增强效果,在表面增强相干反斯托克斯拉曼散射中,不同波长局域场增强空间位置相同的结构结合Fano共振效应,可以实现混合频率共振模式,使得表面增强相干反斯托克斯拉曼散射总的增强因子得到大幅度提高。采用FDTD软件系统研究了对称的交叉蝴蝶结Au纳米结构的Fano共振效应,该效应使得交叉蝴蝶结结构中心位置附近的电场强度得到大幅度的增强,把该结构应用到表面增强相干反斯托克斯拉曼散射中,可以使表面增强相干反斯托克斯拉曼散射信号的增强因子高达1013,达到单分子检测的水平。 相似文献
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The dynamics of the Resonant Raman Scattering (RRS) of multimode broadband lasers is described and resolved without neglecting the phase and cavity effects. The multimode pump structure leads to an equivalent Raman structure by mixing interaction. When the stokes and the pump modes have the same phase, the forward multimodal Raman scattering shows a gain equivalent to the gain of a single mode pump with an equivalent mean power, so that in a Raman resonator the Raman modes can be synchronously amplified to the saturated power until the de phasing destroys the Raman conversion. All these effects have been experimentally observed. Besides an incoherent scattering process is always present in competition with the coherent one. 相似文献
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We have obtained continuously tunable coherent radiation in the1-12 mu m region via sequential Raman scattering of pulsed-dye-laser radiation in hydrogen. A multiple-pass-cell was used to enhance the Raman gain and produce an overall quantum conversion efficiency of at least 45 percent in the wavelength range from 0.9 to 5μm. At 5 μm, an energy output of 1 mj in a 7 ns pulse at a 10 Hz repetition rate has been obtained. Inherent four-wave mixing initiates the sequential Stokes conversion to the infrared and produces single transverse mode (TEM00 ) radiation in a 0.2 cm-1bandwidth. We have developed a nonlinear model of the process that includes the effects of diffraction, four-wave mixing, and temporal pulse shape and gives numerical outputs in agreement with experiment. 相似文献
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A convenient variation of Raman-induced Kerr effect spectroscopy (RIKES) which overcomes many of the previous limitations of coherent Raman spectroscopy is introduced. Quantum limited signal-to-noise ratios may be approached by the use of optical heterodyne detection (OHD). Detector current, linearly proportional and phase sensitive to the third-order nonlinear susceptibility, and linearly proportional to the Raman scattering cross section, is produced. Heterodyne detection in coherent Raman spectroscopy enables the detection of weak Raman signals that would otherwise be obscured by noise resulting from background sources. 相似文献
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斯托克斯光种子法固体相干反斯托克斯拉曼频移器的理论研究 总被引:1,自引:0,他引:1
以波动方程和受激拉曼散射(SRS)物质方程为基础,采用光种子法,建立了固体相干反斯托克斯拉曼频移器的归一化耦合波方程,研究了晶体中反斯托克斯光转换效率。在脉冲抽运条件下分析了归一化增益系数G、归一化相位失配系数ΔK以及一阶斯托克斯光种子的归一化光场振幅ψs0三个变量对固体相干反斯托克斯拉曼频移器的影响,并作出了一系列相应曲线,由所得曲线估算了各归一化变量的合理取值范围。分析结果表明,在ΔK=0时,通过增大sψ0来打破拉曼增益抑制的影响,其转换效率峰值可达到44%。而当sψ0较弱时,可选取合适的相位失配系数,反斯托克斯光转换效率可达40%。 相似文献
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用单次脉冲非稳腔空间增强探测CARS技术测量火焰温度 总被引:6,自引:0,他引:6
采用宽带相干反斯托克斯拉曼散射(CARS)技术测量了甲烷-空气预混火焰温度场分布,并分析了温度测量的不确定度.建立的宽带CARS实验系统采用非稳腔空间增强探测(USED)相位匹配构造,其横向空间分辨率约0.1 mm,纵向空间分辨率约3 mm,该系统能实现10 Hz重复频率测量火焰瞬时温度.采用宽带非稳腔空间增强探测CARS在甲烷-空气预混火焰中获得了单次激光脉冲的高信噪比氮气Q支CARS实验谱,用CARS理论计算软件拟合理论谱和实验谱确定了预混火焰的温度随高度的分布,采用单次激光脉冲的氮气Q支CARS实验谱测量火焰温度的不确定度小于5%. 相似文献
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相干反斯托克斯拉曼散射(CARS)以其散射强度高、方向性好、背景干扰小等优点成为分子研究的有力工具,CARS显微镜不仅可以对样品进行光谱研究,还可以对其进行功能性成像.提高了分子分析的信息量。介绍了CARS显微术的理论结果、不同结构及其在生物学领域的应用等。 相似文献