Induced optical spatial solitons

We show that under suitable conditions, a weak nondegenerate probe may become spatially confined in a Doppler-broadened medium composed of two-level atoms due to the effect of a strong resonant copropagating pump beam. The induced spatial solitons result from the interplay of diffraction and induced focusing of the probe. Realistic conditions that include effects of probe absorption and pump reshaping on propagation are examined. In order to avoid absorption of the near-resonant probe, which would make the strong induced focusing unobservable, the unique properties of the dead zone are exploited.