Rotational Raman scattering

In a diatomic or linear polyatomic molecule rotational Raman scattering obeys the selection rule... 

The value of 10 is determined by molecular and particulate (cloud and aerosol) scattering, and surface reflection. A small fraction of the molecular scattering is the non-conservative Rotational Raman scattering (RRS) that partially fills the solar Fraunhofer lines in the scattered radiation, creating what is commonly known as the Ring effect [15] As a result, the ratio Iq/F, where F is the extraterrestrial solar flux, contains structure that is correlated with solar Fraunhofer lines. By separating these effects, one can write... 

Joiner, J. and Bhartia, P.K. (1995) The Determination of Cloud Pressures from Rotational-Raman Scattering in Satellite Backscatter Ultraviolet Measurements, J. Geophys. Res., 100, pp. 23,019-23,026. 

Joiner, J., Bhartia, P.K., Cebu la, R.P., Hilsenrath, E McPeters, R.D., and Park, H. (1995) Rotational-Raman Scattering (Ring Effect) in Satellite Backscatter Ultraviolet Measurements, Appl. Opt., 34, pp. 4513-4525. 

In a similar fashion, pure rotational Raman scattering can... 

Analysis of experimental rotational Raman scattering from N 0and H has been used to determine temperatures in premixed laboratory flames (1,2). Temperatures based upon rotational Raman scattering from N and 02 had lower uncertainties (1-4%) than those based upon vibrational Raman scattering (3-9%) because rotational Raman scattering is generally more intense and gives rise to many more transitions. However, careful application of Raman intensity theory is required. 

Figure 1. Rotational—vibrational line strength correction factors for pure rotational Raman scattering (fM)0 and for O-, S-, and Q-branch vibrational Raman scattering (foh fots, and folQ). The value J is the rotational quantum number of the initial level (O), Stokes (A), anti-Stokes.

Figure 2. Temperature-analysis plot for rotational Raman scattering from Ot in an Hr-Ot premixed flame. The experimental spectrum is in Figure 5 of Ref. 1. All data are corrected for centrifugal distortion (---), analysis without consid-...

A. D. Buckingham and G. C. Tabisz. Collision induced rotational Raman scattering. Opt. 

S. M. El-Sheikh, N. Meinander, and G. C. Tabisz. Induced rotational Raman scattering and the dipole-octopole polarizability of SF. Chem. Phys. Lett., 775 151-155 (1985). 

D. P. Shelton and G. C. Tabisz. Binary collision induced light scattering by isotropic molecular gases II. Molecular spectra and induced rotational Raman scattering. Molec. Phys., 40 299-308 (1980). 

A special remark should be made concerning the transitions without changes of the energy of the internal degrees of freedom, i.e., about pure rotational Raman scattering. In the case of an even number of electrons, such transitions are possible if in the expansion of the even (odd) (with respect to time reversal) tensor operator C 71 there are representations contained in the symmetric [P] (antisymmetric P ) quadrate of the representation T. In the case of an odd number of electrons, at least one of the representations T in the expansion of the even (odd) operator C 71 (with respect to time reversal) is contained in P ([P]). 

Let us use these selection rules for investigating the main features of the Rayleigh and pure rotational Raman scattering by spherical-top molecules in the lowest vibronic states (Ogurtsov et al., 1978). The polarizability tensors dif2i and can be expanded into components of irreducible tensor operators that in cubic groups transform as E, T2, and T, respectively. Here the behavior of the operators dir 71 with respect to time reversal 0 has to be taken into consideration. To do this, we use the explicit form of the operator djj(a>) in Cartesian coordinates ... 

We recall that our time-resolved data and also the IR results contain a possible contribution of vibrational relaxation, while FIR spectroscopy and rotational Raman scattering do not. 

If the initial and final energy states involved in a Raman transition belong to the rotational level manifold of two different vibrational states, then slightly different conditions than those for pure rotational Raman scattering are encountered in observing the related spectra. 

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