Kim Doyeon, Choi Dae Sik, Kwon Jiwoong, Shim Sang-Hee, Rhee Hanju, Cho Minhaeng
Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) , Seoul 02841, Republic of Korea.
Department of Chemistry, Korea University , Seoul 02841, Republic of Korea.
J Phys Chem Lett. 2017 Dec 21;8(24):6118-6123. doi: 10.1021/acs.jpclett.7b02752. Epub 2017 Dec 7.
A three-beam femtosecond stimulated Raman scattering (SRS) scheme is formulated and demonstrated to simultaneously induce two different SRS processes associated with Raman-active modes in the same molecule. Two SR gains involving a common pump pulse are coupled and compete: As one of the Stokes beam intensities increases, the other SRS is selectively suppressed. We provide theoretical description and experimental evidence that the selective suppression behavior is due to the limited number of pump photons used for both of the two SRS processes when an intense depletion beam induces one SRS process. The maximum suppression efficiency was ∼60% with our experimental setup, where the SR gain of the ring breathing mode of benzene is the target SRS signal, which is allowed to compete with another SRS process, induced by an intense depletion beam, of the CH stretching mode. We anticipate a potential of this new switching-off concept in super-resolution label-free microscopy.
一种三光束飞秒受激拉曼散射（SRS）方案被提出并得到验证，该方案能在同一分子中同时诱导与拉曼活性模式相关的两种不同SRS过程。涉及共同泵浦脉冲的两个SR增益相互耦合且相互竞争：随着其中一个斯托克斯光束强度增加，另一个SRS会被选择性抑制。我们提供了理论描述和实验证据，表明这种选择性抑制行为是由于当一个强耗尽光束诱导一个SRS过程时，用于两个SRS过程的泵浦光子数量有限。在我们的实验装置中，最大抑制效率约为60%，其中苯的环呼吸模式的SR增益是目标SRS信号，它与由强耗尽光束诱导的CH伸缩模式的另一个SRS过程相互竞争。我们预计这种新的关闭概念在超分辨率无标记显微镜中有潜在应用。
