A theoretical analysis is made of the compensation of a positive nonlinear refractive index of insulators containing impurities by saturation of the refractive index in the anomalous dispersion region. The exact solutions are obtained for self-similar amplification of a laser pulse under conditions of homogeneous broadening of a resonant transition. It is shown that profiling of the time envelope of a steady-state bleaching wave of a saturable absorber together with detuning of the pulse frequency upward from resonance makes it possible to increase the threshold of small-scale self-focusing.