Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea.
Department of Chemistry, Korea University, Seoul 02841, Korea.
J Phys Chem B. 2020 Apr 30;124(17):3583-3590. doi: 10.1021/acs.jpcb.0c03080. Epub 2020 Apr 20.
Recently, we introduced a new switching-off technique applicable to subdiffraction-limited coherent Raman imaging, where a coherent anti-Stokes Raman scattering (CARS) signal can be selectively suppressed via competitive stimulated Raman scattering (SRS) processes between vibrational modes of a single molecular species. Here, we show that such a three-beam CARS suppression can be made via double SRS processes between vibrational modes of heteromolecular species, a mixture of paraffin oil and benzene. We achieve more than 80% suppression of the pump-Stokes-beam CARS signal for the ring-breathing mode (target mode) of benzene when the C-H stretching mode (acceptor mode) of paraffin oil is used to deplete the pump photons via the pump-depletion-beam SRS process. The freedom in the choice of acceptor mode for depletion, which could be a critical advantage of the present switching-off scheme, can be of use for overcoming current challenges of depletion-based super-resolution coherent Raman imaging of biomolecules.
最近,我们引入了一种新的关断技术,适用于亚衍射极限相干拉曼成像,其中可以通过单个分子物种的振动模式之间的竞争受激拉曼散射(SRS)过程来选择性地抑制相干反斯托克斯拉曼散射(CARS)信号。在这里,我们表明,通过异分子物种的振动模式之间的双 SRS 过程,可以实现这种三光束 CARS 抑制,异分子物种是石蜡油和苯的混合物。当使用石蜡油的 C-H 伸缩模式(接受体模式)通过泵浦损耗光束 SRS 过程耗尽泵浦光子时,我们实现了苯的环呼吸模式(目标模式)的泵 - 斯托克斯光束 CARS 信号的超过 80%的抑制。对于损耗的接受体模式的选择的自由度,这可能是本关断方案的一个关键优势,可以用于克服基于损耗的生物分子超分辨率相干拉曼成像的当前挑战。