Absolute Cross Sections of Liquids from Broadband Stimulated Raman Scattering with Femtosecond and Picosecond Pulses
Absolute Cross Sections of Liquids from Broadband Stimulated Raman Scattering with Femtosecond and Picosecond Pulses
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DOI：
10.1021/acs.analchem.0c01785
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发表时间：
2020-08-04
影响因子：
7.4
通讯作者：
Elles, Christopher G.
中科院分区：
文献类型：
--
作者：
Burns, Kristen H.;Srivastava, Prasenjit;Elles, Christopher G.
宽带受激拉曼散射（SRS）在应用中经常被观察到，使用非线性光谱来探测复杂系统的组成或动力学。无论有意还是无意地测量SRS响应，作为背景信号，相对散射强度提供了目标分子种群分布的定量测量。在这些应用中，溶剂散射是确定绝对浓度的有价值的内部参考，但是精确的横截面仅报道了有限数量的选择溶剂中的过渡，并且使用窄带连续波或纳秒光源的自发拉曼散射进行测量。这项工作报道了使用宽带SRS在488 nm的飞秒和皮秒拉曼泵脉冲测量和分析环己烷、二甲二甲醚、乙腈、甲醇、水、苯和甲苯在500-4000 cm（-1）的频率范围内的绝对拉曼散射截面。改变拉曼泵浦脉冲的持续时间，从80秒到100秒，证实了横截面与光谱带宽无关，范围类似于250到100秒
Broadband stimulated Raman scattering (SRS) is often observed in applications that use nonlinear spectroscopy to probe the composition or dynamics of complex systems. Whether the SRS response is measured intentionally or unintentionally, as a background signal, the relative scattering intensities provide a quantitative measure of the population profile of target molecules. Solvent scattering is a valuable internal reference for determining absolute concentrations in these applications, but accurate cross sections have been reported for only a limited number of transitions in select solvents and were measured using spontaneous Raman scattering with narrowband continuous wave or nanosecond light sources. This work reports the measurement and analysis of absolute Raman scattering cross sections spanning the frequency range of 500-4000 cm(-1) for cyclohexane, DMSO, acetonitrile, methanol, water, benzene, and toluene using broadband SRS with femtosecond and picosecond Raman pump pulses at 488 nm. Varying the duration of the Raman pump pulses from similar to 80 fs to >1 ps confirms that the cross sections are independent of the spectral bandwidth across the range of similar to 250 to