Ultrafast Coherent Raman Spectroscopy
During the past decade, time resolved coherent methods have attracted much interest for the study of fast dynamic processes. In particular, time resolved coherent Raman scattering allowed to measure — in the time domain — rapid dephasing processes of molecular vibrations in liquids and elucidated various line-broadening mechanisms /1-4/. It is the aim of this paper to focus attention on two more recent subjects. While time resolved Raman scattering is a method working in the time domain, it allows to obtain valuable information in the frequency domain /5, 6/. The results of coherent experiments in the time domain have to be transformed by appropriate methods, e.g. by Fourier transformation, to show properties of the investigated system in the frequency domain. We present here two different approaches to relate time and frequency domain: (i) A time resolved coherent Raman experiment is performed and the spectrum of the coherently scattered light is recorded, (ii) A numerical transformation is applied to coherent data of high time resolution giving precise values of frequency differences of vibrational modes separated by several terahertz. Both techniques give — when applied in an appropriate way —results superior to steady- state spontaneous spectroscopy.
KeywordsExciting Force Coherent Signal Raman Cross Section Stokes Pulse Coherent Amplitude
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- 5.W. Zinth, W. Kaiser: In Organic Molecular Aggregates, eds. R.Reinecker, H.Haken, H. C.Wolf, Solid State Science, Vol. 49, ( Springer, New York 1983 ) p. 124Google Scholar
- 16.R. Leonhardt, W. Holzapfel, W. Zinth, W. Kaiser: Chem. Phys. Lett., to be published 1987Google Scholar