Time-resolved coherent anti-Stokes Raman

Joe T and Albrecht A C 1993 Femtosecond time-resolved coherent anti-Stokes Raman spectroscopy of liquid benzene a Kubo relaxation function analysis J. Chem. Phys. 99 3244-51... 

Volkmer, A., Book, L., and Xie, X. S. 2002. Time-resolved coherent anti-Stokes Raman scattering microscopy Imaging based on Raman free induction decay. Appl. Phys. Lett. 80 1505-7. 

Time-resolved coherent anti-Stokes Raman scattering has produced much important information on the dynamics of molecular vibrations and rotations (Laubereau and Kaiser, 1978 Duppen et al., 1983 Akhmanov et al., 1985 Angeloni et al., 1988). Particularly vibrational dephasing time constants in liquids and solids could be determined with this technique (Laubereau et al., 1978 Kohles and Laubereau, 1987 Weber and Rice, 1988 Bron et al., 1989). In these experiments pump and tunable Stokes beams serve to produce... 

Time resolved coherent anti-Stokes Raman spectroscopy of condensed matter has been recently extended to the femtosecond domain allowing direct and detailed studies of the fast relaxation processes of molecular vibrations in liquids. The vibrational phase relaxation (dephasing) is a fundamental physical process of molecular dynamics and has attracted considerable attention. Both experimental and theoretical studies have been performed to understand microscopic processes of vibrational dephasing. Developments in ultrafast coherent spectroscopy enables one now to obtain direct time-domain information on molecular vibrational dynamics. Femtosecond time-resolved coherent anti-Stokes Raman scattering measuring systems have been constructed (see Sec. 3.6.2.2.3) with an overall time resolution of less than 100 fs (10 s). Pioneering work has been per-... 

Marko, K. A., and Rimai, L. "Space and Time-Resolved Coherent Anti-Stokes Raman Spectroscopy for Combustion Diagnostics." Optic Society of America 4, no. 7 (1979) 211-13. 

NH2 radicals, generated by photolysis of NH3 (0.5 mbar) with an ArF exciplex laser at 193 nm, were detected by time-resolved, coherent anti-Stokes Raman spectroscopy in the NH stretch regions at 3334 and 3220 cm [1]. Two Raman bands of NH2, V3 = 3276 2 and V2 = 1471 2 cm were observed in solid ammonia at 77 K after irradiation with an atomic aluminium beam [2]. 

Zadoyan R, Kohen D, Lidar D, Apkarian VA (2001) The manipulation of massive ro-vibronic superpositions using time-frequency-resolved coherent anti-stokes raman scattering (tfrcars) from quantum control to quantum computing. Chem Phys 266 323... 

Several types of time-resolved Raman spectroscopies have been reported and reviewed by Hamaguchi and co-workers and Hamaguchi and Gustafson. These include pump-probe spontaneous and time-resolved coherent Raman spectroscopy of the anti-Stokes and Stokes varieties [coherent anti-Stokes Raman spectroscopy (CARS) and coherent Stokes Raman spectroscopy (CSRS)], respectively). Here we will focus on pump-probe time-resolved spontaneous Raman spectroscopy. 

Table II Space- and Time-Resolved Measurements from Inelastic Light Scattering. All methods are suitable for nonequilibrium conditions. Here, RS refers to Raman scattering, CARS to coherent anti-Stokes Raman spectroscopy, and RIKES to Raman-induced Kerr effect.

In this chapter we will first discuss coherent anti-Stokes Raman scattering (CARS) of simple liquids and binary mixtures for the determination of vibrational dephasing and correlation times. The time constants represent detailed information on the intermolecular interactions in the liquid phase. In the second section we consider strongly associated liquids and summarize the results of time-resolved IR spectroscopy (see, e.g., Ref. 17) on the dynamics of monomeric and associated alcohols as well as isotopic water mixtures. 

Figure 1 Schematic representation of a time-resolved coherent Raman experiment, (a) The excitation of the vibrational level is accomplished by a two-photon process the laser (L) and Stokes (S) photons are represented by vertical arrows. The wave vectors of the two pump fields determine the wave vector of the coherent excitation, kv. (b) At a later time the coherent probing process involving again two photons takes place the probe pulse and the anti-Stokes scattering are denoted by subscripts P and A, respectively. The scattering signal emitted under phase-matching conditions is a measure of the coherent excitation at the probing time, (c) Four-photon interaction scheme for the generation of coherent anti-Stokes Raman scattering of the vibrational transition.

Fig. 5.2 Energy diagrams of coherent anti-Stokes Raman scattering (CARS) and time-resolved CARS...

Among approaches in vibrational spectroscopy are differential and time-resolved IR and Raman spectroscopy, coherent anti-Stokes Raman scattering (CARS), Fourier transform infrared spectroscopy (FT-IR) multidimensional IR and RR spectroscopy, two-dimensional infrared echo and Raman echo [56], and ultrafast time-resolved spontaneous and coherent Raman spectroscopy the structure and dynamics of photogenerated transient spedes [50, 57]. 

Recently, the femtosecond time-resolved spectroscopy has been developed and many interesting publications can now be found in the literature. On the other hand, reports on time-resolved vibrational spectroscopy on semiconductor nanostructures, especially on quantum wires and quantum dots, are rather rare until now. This is mainly caused by the poor signal-to-noise ratio in these systems as well as by the fast decay rates of the optical phonons, which afford very fast and sensitive detection systems. Because of these difficulties, the direct detection of the temporal evolution of Raman signals by Raman spectroscopy or CARS (coherent anti-Stokes Raman scattering) [266,268,271-273] is often not used, but indirect methods, in which the vibrational dynamics can be observed as a decaying modulation of the differential transmission in pump/probe experiments or of the transient four-wave mixing (TFWM) signal are used. 

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