Boosting strong-coupling stimulated Brillouin amplification performance using an external magnetic field

Abstract

This article presents a method for improving the amplification performance of strong-coupling stimulated Brillouin scattering by adding an external static magnetic field longitudinal to the laser propagation direction. Simulation results show that when the laser intensity is low, the output seed intensity can be increased by applying an external magnetic field and a right-hand circularly polarized laser pulse. When the seed intensity is higher, the amplification enters the regime of relativistic electron nonlinearity, the amplification oscillates, and the portion of the seed that is amplified moves from the first peak to the second and then the third. Under these circumstances, a reversed magnetic field helps to obtain a higher output intensity and a smoother output pulse profile. Adjusting the magnetic field dynamically, such as by using a double-pass scheme, combines these two advantages and maximizes the intensity enlarging and profile smoothing of the output pulse.