外文题目: Surface-Enhanced Impulsive Coherent Vibrational Spectroscopy
作者: Du, Juan; Harra, Juha; Virkki, Matti; Makela, Jyrki M.; Leng, Yuxin; Kauranen, Martti; Kobayashi, Takayoshi
刊名: Sci Rep
年: 2016 卷: 6 文章编号：36471
英文关键词:

STOKES-RAMAN-SCATTERING; CYCLE PULSE LASER; CHEMICAL ENHANCEMENT; TRANSITION-STATES; EXCITED-STATE; SERS; MECHANISM; DYNAMICS; SPECTRA; SILVER
英文摘要:
Surface-enhanced Raman spectroscopy (SERS) has attracted a lot of attention in molecular sensing because of the remarkable ability of plasmonic metal nanostructures to enhance the weak Raman scattering process. On the other hand, coherent vibrational spectroscopy triggered by impulsive excitation using ultrafast laser pulses provides complete information about the temporal evolution of molecular vibrations, allowing dynamical processes in molecular systems to be followed in "real time". Here, we combine these two concepts and demonstrate surface-enhanced impulsive vibrational spectroscopy. The vibrational modes of the ground and excited states of poly[2-methoxy5-( 2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), spin-coated on a substrate covered with monodisperse silver nanoparticles, are impulsively excited with a sub-10 fs pump pulse and characterized with a delayed broad-band probe pulse. The maximum enhancement in the spectrally and temporally resolved vibrational signatures averaged over the whole sample is about 4.6, while the realtime information about the instantaneous vibrational amplitude together with the initial vibrational phase is preserved. The phase is essential to determine the vibrational contributions from the ground and excited states.


文献类型: 期刊论文
正文语种: English
收录类别: SCI
DOI: 10.1038/srep36471


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