The intensity-dependent refractive index is calculated for a Kerr-like medium composed of a closed three-level atomic system in V-configuration and it is shown that two optical waves of different frequencies can be mutually-trapped in the form of bright and dark spatial solitons.
We consider an optical medium consisting of a periodic refractive-index grating and a periodic set of thin layers of two-level systems resonantly interacting with the electromagnetic field. Recently, it has been shown that such a system gives rise to a vast variety of stable bright solitons. In this work, we demonstrate that the system has another very unusual property: stable bright solitons can coexist with stable continuous-wave (cw) states and stable dark solitons (DS's). Depending on the parameters' values, a DS frequency band coexists (without overlap) with one or two bright-soliton bands. Quiescent (standing) DS's are found in an analytical form, and moving ones are obtained numerically. Simulations show that a considerable part of the DS solutions are completely stable against arbitrary small perturbations. The fact that this system supports both stable bright and dark solitons for the same parameters values may find interesting applications in photonics.
We present the theoretical model of coherent interactions of the light beams in a two-level resonant medium, taking into account a spatial-periodic modulation of the parameters of nonlinear medium in an interference field as well as nonlinear behavior of refractive index and absorption coefficient due to optical bleaching. As evidenced by the results of investigations described in this work, the process of the light beams interaction via scattering from dynamically induced optical gratings in two-level resonant medium is characterized by a number of interesting features like mutual attraction and repulsion, irradiation of additional beams probably due to soliton-soliton diffraction mode, formation of dark spatial solitons in the mode of defocusing interaction that can be used for all-optical control over the spatial structure of laser beams. Formation of bound states of spatial cavity solitons upon intracavity four-wave mixing and possibilities for control over all-optical soliton-based operations are also discussed.
We present the theoretical model of coherent interactions of the light beams in a two-level resonant medium, taking into account a spatial-periodic modulation of the parameters of nonlinear medium in an interference field as well as nonlinear behavior of refractive index and absorption coefficient due to optical bleaching. As evidenced by the results of investigations described in this work, the process of light beams interaction via scattering from dynamically-induced optical gratings in two-level resonant medium is characterized by a number of interesting features like mutual attraction and repulsion, irradiation of additional beams probably due to soliton-soliton diffraction mode, formation of dark spatial solitons in the mode of defocusing interaction that can be used for all-optical control over the spatial structure of laser beams