We report that the tail modulation of Stokes pulses in the high-energy stimulated Brillouin scattering pulse compression can be suppressed by controlling effective pulse width of the pump. It is shown through numerical simulations and validated experimentally that the effective pulse width is an appropriate parameter, which determines the generation of tail modulation. The effective pulse width broaden as the increase of energy. This mechanism leads to the amplification of Stokes tail edge and it is the cause of tail modulation.
