We investigate both experimentally and numerically the evolution of slow light in the limit of high stimulated-Brillouin-scattering gain, as in a Brillouin fiber laser. The Stokes pulse transit time is measured to decrease and the resonant modes to shift to higher frequencies with increasing pump power. Numerical simulations reveal that pump depletion introduces a nonuniform group index across the Stokes pulse as it interacts with the pump, the index being greater for the leading edge and decreasing progressively towards the trailing edge in proportion to the remaining pump power. This results in a progressive acceleration of the Stokes pulse from slow to fast as it propagates through the cavity.
© 2008 Optical Society of America
Lasers and Laser Optics
Original Manuscript: April 25, 2008
Revised Manuscript: July 24, 2008
Manuscript Accepted: July 29, 2008
Published: September 9, 2008
R. K. Pattnaik and Jean Toulouse, "Accelerated propagation of Stokes pulses in a Brillouin fiber laser: pump power dependence of cavity modes," J. Opt. Soc. Am. B 25, 1593-1601 (2008)