Utilizing Microcavities To Suppress Third-Order Cascades in Fifth-Order Raman Spectra
Utilizing Microcavities To Suppress Third-Order Cascades in Fifth-Order Raman Spectra
复制标题
利用微腔抑制五阶拉曼光谱中的三阶级联
DOI：
10.1021/acs.jpclett.7b01129
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Mukamel, Shaul
中科院分区：
文献类型：
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作者：
Zhang, Zhedong;Bennett, Kochise;Chernyak, Vladimir;Mukamel, Shaul
凝聚相中的非线性光信号通常伴随着一系列低阶过程，称为级联，它们具有相同的相位匹配和对输入场的功率依赖性，因此很难区分。为了揭示所需的非线性信号而抑制级联一直是多维拉曼光谱中的一个主要挑战，即，χ(5)信号被两个χ(3)过程的乘积给出的级联信号所掩盖。由于级联源于分子之间虚拟光子的交换，因此可以通过在光学微腔中进行实验来操纵它，从而改变辐射场模式的密度。使用量子电动力学 (QED) 处理，我们证明可以极大地抑制 χ(3) 级联贡献。通过优化腔体尺寸和输入脉冲方向，我们表明可以抑制高达 99.5% 的级联信号。
Nonlinear optical signals in the condensed phase are often accompanied by sequences of lower-order processes, known as cascades, which share the same phase matching and power dependence on the incoming fields and are thus hard to distinguish. The suppression of cascading in order to reveal the desired nonlinear signal has been a major challenge in multidimensional Raman spectroscopy, that is, the χ(5)signal being masked by cascading signals given by a product of two χ(3)processes. Because cascading originates from the exchange of a virtual photon between molecules, it can be manipulated by performing the experiment in an optical microcavity which modifies the density of radiation field modes. Using a quantum electrodynamical (QED) treatment, we demonstrate that the χ(3)cascading contributions can be greatly suppressed. By optimizing the cavity size and the incoming pulse directions, we show that up to ∼99.5% suppression of the cascading signal is possible.