Suppression of stimulated Brillouin scattering by multicolor alternating-polarization bundle light in inertial confinement fusion

Abstract

This study proposes a novel method to mitigate stimulated Brillouin scattering (SBS) using multicolor alternating-polarization bundle light. The bundle light combines multiwavelength, spike trains of uneven duration and delay for a single beam to multicolor alternating polarization for bundle beams. SBS suppression is verified using a three-dimensional large-scale laser plasma code. The numerical results show that the SBS reflectivity can be decreased by nearly two orders in low density plasma. The proposed method can extend the repetition time of a single beam from several picoseconds to tens of picoseconds. Moreover, it has potential applications in inertial confinement fusion research.

Suppression of stimulated Brillouin and Raman scatterings using an alternating frequency laser and transverse magnetic fields

“…[26] All these methods or combinations of them have been widely used to control the peak intensities of laser spatial speckles and hence to suppress instabilities in ICF, but they cannot reduce LPIs to a tolerable level. [27,28] Recently, some new theoretical schemes for suppressing LPIs by changing lasers have also been proposed, including various broadband technologies, [29][30][31][32] two-color incident light, [33][34][35] spike trains of uneven duration and delay (STUD), [36][37][38][39] rotating polarization, [40][41][42] alternating polarization, [43,44] the discretely changing phase, [45] etc. It can be seen that in order to reduce the development of LPIs, existing schemes focus on changing the laser frequency, amplitude, polarization direction and phase.…”