Effect of acoustic wave inertia on stokes pulse delay via stimulated Brillouin scattering: implications to slow light

In this paper we show through analytic theory that there exist no conditions which can give rise to group index induced delay of the Stokes pulse. Rather the delay is that arising through gain build-up. We have obtained the dynamic form of the output Stokes pulses and their delay, along with group index spectra induced by the Stokes-pump interaction. The spectra of a Stokes pulse and the group index induced by this pulse for different t_p, are calculated. We therefore conclude that regardless of the duration of the input Stokes pulse the pulse delays associated with SBS amplification of a Stokes pulse cannot be attributed to SBS-induced group delay. They are predominantly a consequence of the phenomenon of SBS build-up.