“Slow Light” in stimulated Brillouin scattering: on the influence of the spectral width of pump radiation on the group index: Comment

In a recent paper by Kovalev et al [Optics Express 17, 17317 (2009)] the coupled equations describing stimulated Brillouin scattering (SBS) were solved in the Fourier domain. The main conclusion driven by the authors was that SBS pump spectral broadening was not effective in increasing the interaction bandwidth. While the calculations are essentially correct, the interpretation of the results leads to erroneous conclusions.