Raman-induced Kerr effect spectroscopy

H) RAMAN INDUCED KERR EFFECT SPECTROSCOPY (RIKES)... 

Rikes. See Raman-induced Kerr-effect spectroscopy. 

Before melting and for some time after only the band at 625 cm of the AA [C4CiIm]+ cation was observed in the 600-630 cm i region. Gradually 603 cm i band due to the GA conformer became stronger. After about 10 min the AA/GA intensity ratio became constant. The interpretation [50] is that the rotational isomers do not interconvert momentarily at the molecular level. Most probably it involves a conversion of a larger local structure as a whole. The existence of such local structures of different rotamers has been found by optical heterodyne-detected Raman-induced Kerr-effect spectroscopy (OHD-RIKES) [82], Coherent anti-Stokes Raman scattering (CARS) [83],... 

The following section contains a more detailed treatment of the theory behind the nonresonant spectroscopy of liquids. This will be followed by a description of the experimental implementation and data analysis techniques for a common OKE scheme, optical-heterodyne-detected Raman-induced Kerr-effect spectroscopy (22). We will then discuss the application of this technique to the study of the temperature-dependent dynamics of simple liquids composed of symmetric-top molecules. 

Cong P, Deuel HP, Simon JD. Structure and dynamics of molecular liquids investigated by optical-heterodyne detected Raman-induced Kerr effect spectroscopy (OHD-RIKES). Chem Phys Eett 1995 240 72-78. 

Borysow J, Taylor RH, Keto JW (1989) Raman-induced Kerr effect spectroscopy of solutions. J Raman Spectrosc 20(4) 203-208... 

There are several classes of optical effects induced by an internal perturbation, such as saturation of absorption, coherent Raman spectroscopy, multi-photon absorption processes, coherent transient spectroscopy (see Table 0.3). Section 5.1 of this chapter deals with saturation of absorption and multi-photon absorption processes. Section 5.2 outlines the principles of coherent anti-Stokes Raman spectroscopy (CARS), Raman-induced Kerr effect spectroscopy (RIKES), four-wave mixing (FWM), and photon echo. 

RIKES (Raman Induced Kerr Effect Spectroscopy)... 

The nonresonant background prevalent in CARS experiments (discussed above), although much weaker than the signals due to strong Raman modes, can often obscure weaker modes. Another technique which can suppress the nonresonant background signal is Raman induced Kerr-effect spectroscopy or RIKES [%, 97]. 

A new technique to measure low-frequency spectra is optical-heterodyne-detected Raman-induced Kerr-effect spectroscopy (OHD-RIKES). A recent publication by Chang and Cast-ner contains references to previous work within this field [18]. OHD-RIKES is based on a four-wave mixing of femtosecond laser pulses. Spectra obtained by OHD-RIKES reflect the anisotropic part of the Raman polarizability. Thus, the information obtained by OHD-RIKES is very similar to that obtained by low-frequency Raman scattering in an scattering configuration. From a theoretical point of view, the spectral representation obtained from OHD-RIKES measurements corresponds to the I v) representation given in Eq. (3). In Fig. 4 is shown an OHD-RIKES spectrum of liquid A-methylformamide (NMF). In Fig. 5 are shown low-frequency Raman spectra of liquid NMF together with the R(i>),... 

Other Raman-based forms of nonlinear spectroscopy include stimulated Raman gain (SRG) or stimulated Raman scattering, stimulated Raman loss (SRL) or inverse Raman spectroscopy, and Raman induced Kerr effect spectroscopy (RIKES). Some information on these techniques are provided in Table 1. Many of these other forms do not produce light at wavelengths that are different from the input lasers, do not involve phase matching, and may be susceptible to multiple effects that may interfere with the measurement. Consequently, these techniques have not been as widely used as CARS. 

The high power densities available from lasers were found to be capable of inducing a number of strange (nonlinear) Raman effects, though many were of limited applicability to problems in chemistry. Typical examples included SIRS (stimulated inverse Raman scattering), RIKES (Raman induced Kerr effect spectroscopy) and the hyper Raman effect. 

Atom Substitution Effects in Ionic Liquids A Microscopic View by Femtosecond Raman-Induced Kerr Effect Spectroscopy... 

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