Impact of stimulated Brillouin scattering in optical fibers with distributed gain

The equations describing the stimulated Brillouin scattering process in optical fibers with distributed gain, including an equation for the second-order Stokes wave, are numerically solved. An analytical solution for the case of no net gain or loss is also presented. We note that the presence of distributed gain along the fiber leads to a nonmonotonous evolution of the signal power and to ready generation of multiple Stokes orders. The effect of broadening the signal spectrum, as well as the influence of a copropagating or counterpropagating signal are also examined