Line coupling in anisotropic Raman branches

Direct connection between collisional Raman cross sections and state‐to‐state rotational ones permits, within the sudden approximation, to evidence drastic decouplings from isotropic to anisotropic lines. These decouplings are consistent with the results obtained by using the strong collision model. Convenient energy corrections to the sudden approximation are used for N2 to calculate the resulting effects on the isotropic and anisotropic Q‐branch profiles in a large density range (several hundred bars). The comparison of the calculations with experimental coherent anti‐Stokes Raman scattering (CARS) and stimulated Raman (SRS) spectra of nitrogen exhibits a good agreement. Such effects could have applications in optical diagnostics.

[1]  M. L. Strekalov,et al.  Comparison and analysis of rotationally inelastic collision models describing the Q-branch collapse at high density , 1993 .

[2]  J. Hartmann,et al.  State‐to‐state rotational cross sections in vibrational modes. Application to the infrared Q‐branch profile for the (11 10)I←(00 00) 12C16O2 bending band , 1993 .

[3]  D. Ben‐Amotz,et al.  Vibrational frequency shifts of fluid nitrogen up to ultrahigh temperatures and pressures , 1993 .

[4]  Temkin,et al.  Angular-momentum coupling in spectroscopic relaxation cross sections: Consequences for line coupling in bending bands. , 1993, Physical review. A, Atomic, molecular, and optical physics.

[5]  B. Lavorel,et al.  Stimulated Raman spectroscopy of the Q branch of nitrogen at high pressure: collisional narrowing and shifting in the 150–6800 bar range at room temperature , 1992 .

[6]  J. Looney,et al.  Self‐broadening and line mixing in HCN Q branches , 1992 .

[7]  A. Henry,et al.  Line mixing in the Q branches of the ν1+ν2 band of nitrous oxide and of the (1110)I←(0220) band of carbon dioxide , 1992 .

[8]  A. Weber,et al.  Spectroscopy of the Earth's Atmosphere and Interstellar Medium , 1992 .

[9]  L. Bonamy,et al.  Local scaling analysis of state‐to‐state rotational energy‐transfer rates in N2 from direct measurements , 1991 .

[10]  P. Monot,et al.  Theory of rotational line strengths in coherent anti-Stokes Raman spectroscopy , 1991 .

[11]  S. Temkin,et al.  Does the Hubbard relation hold in the liquid cage model , 1991 .

[12]  A. Burshtein,et al.  Rotational relaxation in gases and its spectral manifestations , 1989 .

[13]  R. Clark,et al.  Advances in non-linear spectroscopy , 1988 .

[14]  G. Millot,et al.  A rotational thermalization model for the calculation of collisionally narrowed isotropic raman scattering spectra - application to the SRS N2 Q-branch , 1986 .

[15]  G. Millot,et al.  Rotational collisional line broadening at high temperatures in the N2 fundamental Q-branch studied with stimulated Raman spectroscopy , 1986 .

[16]  B. Gentry,et al.  Rotational collisional narrowing in an infrared CO2 Q branch studied with a tunable-diode laser , 1986 .

[17]  M. Alexander,et al.  Propensity rules in rotationally inelastic collisions of diatomic molecules in 3Σ electronic states , 1983 .

[18]  D. Débarre,et al.  Resonance-enhanced coherent anti-Stokes Raman scattering in C2 , 1983 .

[19]  A. Burshtein,et al.  On the shape of the Q-branch of Raman scattering spectra in dense media. Theory , 1979 .

[20]  W. Murphy,et al.  The ro-vibrational Raman spectrum of water vapour υ2 and 2υ2 , 1977 .

[21]  E. Hara,et al.  Depolarized Rayleigh scattering in gases as a new probe of intermolecular forces , 1968 .

[22]  G. Scoles,et al.  The influence of a magnetic field on the transport properties of gases of polyatomic molecules;: Part I, Viscosity , 1967 .

[23]  J. Kranendonk,et al.  Calculation of the Self-Broadening of Raman Lines due to Dipolar and Quadrupolar Forces , 1963 .