Resonance Raman scattering of the strong laser field from diatomic molecules

Abstract

The authors consider the resonance Raman scattering (RRS) of a strong laser field from a homonuclear diatomic molecule when the incident frequency is in the region of discrete vibronic transitions. Wavefunctions of the homonuclear diatomic molecules in a strong laser field in the multilevel approximation are constructed. These wavefunctions take into account the interaction of a molecules with a number of photons at the same time. The authors construct the scattering tensor in a strong resonance laser field. A new relation for the amplitude of the matrix element of the induced dipole moment of a molecule has been obtained. With the help of the suggested relation the authors have been able to account for the nonlinear effects arising in RRS of a strong laser field from diatomic molecules. The authors influence of the resonance detuning sign on the distribution of the intensity of RRS lines has been established. The approach to resonance 'from above' and 'from below' leads to a significant redistribution of the overtone intensity for some molecules. The principles of selecting the molecules for which there are such situations are discussed. As an example, the amplitudes of the induced dipole moment matrix element and the relative intensities of the Stokes' components of RRS lines for the molecules Cu2 (B1 Sigma u+-X1 Sigma g+ band) and N2 (C3 Pi u-B3 Pi g band) have been calculated.