Suppression of stimulated Brillouin scattering by two perpendicular linear polarization lasers

Abstract

Stimulated Brillouin scattering (SBS) is a basic problem for laser–plasma interactions. In this work, two perpendicular linear polarization lasers with different frequencies are combined to form a new beam. The polarization of the new beam varies between linear and ellipse, while the intensity remains constant. By adopting this method, a significant suppression of SBS is predicted due to the reduction in the effective wave–wave interaction lengths. Additionally, two linearly polarized beams would be easier to use in an experiment than an alternate approach using two circularly polarized beams. The suppression of SBS is modeled with a nonlinear wave–wave coupling model, and the model is verified with 1D particle-in-cell simulations.

Suppression of auto-resonant stimulated Brillouin scattering in supersonic flowing plasmas by different forms of incident lasers*

“…One is to optimize the uniformity of the incident laser spot such as spatial smoothing, spectral dispersion [10] and polarization smoothing, [11,12] the other is to decrease the interaction length of SBS such as the spike trains of uneven duration and delay (STUD), [13] alternating-polarization light, [14] polarization rotation [15] and two perpendicular linear polarization. [16] In this article, polarization rotation and two perpendicular linear polarizations are performed to suppress the absolute growth of auto-resonant stimulated Brillouin scattering. To find the effect of them, several simulations are performed by the 1-D Vlasov code [17] and theories associated with them are deduced.…”