Nonlinear refractive index of atmospheric gases induced by raman scattering of femtosecond pulse on molecular rotational transitions
Yu.N. Ponomarev, S.R. Uogintas
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, 1, Academician Zuev square, Tomsk, 634021, Russia
Keywords: femtosecond pulses, nonresonant interaction, molecules
Abstract
Within the density matrix framework, we obtained an expression for the transient third-order susceptibility and relating refractive index induced by stimulated Raman scattering of femtosecond pulse on molecular rotational transitions. It is explicitly shown that the nuclear sub-system response to the pulse field is anisotropic and delayed in time. Calculated average values of the refractive index n2 for molecular nitrogen (2 × 10–19 cm2/W) and oxygen (4 × 10–19 cm2/W) agree with those available in literature.
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