  We have explored through numerical simulations the amplification of laser
pulses in nonlinear fiber Bragg gratings with gain and normal dispersion. The
distortion of the temporal intensity profile caused by the higher-order
dispersion coefficients is examined. The stabilizing effect of fourth-order
dispersion on pulse propagation is demonstrated. For some conditions, the
amplified pulse shape evolves towards a Bragg similariton, a quasi-parabolic
temporal profile with wave-breaking free temporal characteristics.
