Two-level laser by the interaction of self-induced transparency pulses and surface Anderson localizations of light

Self-induced transparency (SIT) pulses induce a traveling population inversion in two-level atoms. As a rule, the active medium in which the soliton travels has to be homogeneous. Here, we study the effect of a spatially disordered modulation in the refractive index profile that may lead to Anderson localizations. The interplay between the ultrashort SIT pulse, a nonlinear effect, and this kind of disorder-induced mode exhibits intriguing features. Once the SIT pulse is confined in the spatially confined regions, they act as closed cavities for the SIT population inversion. A positive optical feedback mechanism can be thus activated and, as a result, a two-level laserlike emission can be obtained.