Stimulated Molecular Scattering of Light

V. S. Starunov, Immanuil L. Fabelinskii

V. S. Starunov, Immanuil L. Fabelinskii

V. S. Starunov

Kōichi Shimoda

Guang S. He

When a high-intensity laser beam passes through a transparent and homogeneous optical medium, the induced light scattering may manifest the properties of stimulated radiation characterized by threshold requirement, high directionality, and high brightness. This is the stimulated scattering of intense coherent light. Discoveries and studies of various types of stimulated scattering effects have provided a much deeper and more comprehensive understanding of interactions between the intense coherent light and matter. On the other hand, devices based on stimulated Raman scattering, stimulated Brillouin scattering, and stimulated spin-flip Raman scattering can be employed as highly efficient tunable frequency shifters of coherent light. Stimulated Kerr scattering can be used to generate a super-broadband coherent light and to investigate the molecular anisotropy of liquids. In addition, the recently developed stimulated Rayleigh–Bragg scattering and stimulated Mie scattering can significantly reduce the threshold requirement, and provide a highly efficient no-frequency-shift optical phase conjugation wave.

R. M. Herman

The phenomenon of stimulated Rayleigh-wing scattering in anisotropic molecular liquids is analyzed. Representative combinations of polarization for the incident and scattered light are considered. It is shown that in regions where the focused laser beam is intense, saturation occurs in the molecular response to external optical fields, in that perfect alignment of the individual liquid molecules in the optical fields is approached. Accordingly, the nonlinear amplification associated with the stimulated radiation is reduced. The results of the analysis qualitatively explain several important recent observations which are in conflict with previous theroretical predictions. For example, it is shown that the nonlinear gain is considerably greater when the incident light is circularly polarized (the stimulated radiation being circularly polarized in the reverse sense) than it is when the incident light is linearly polarized. Despite saturation, sufficient amplification exists in the former case to allow the efficient conversion of incident to stimulated Rayleigh light at moderate power levels.