Spatial Modulation of Four-Wave Mixing Solitons

Abstract

Since the cross-Kerr and self-Kerr nonlinearities are greatly enhanced in the multi-level electromagnetically-induced transparency (EIT) systems, the spatial diffractions of the probe, as well as the generated four-waving mixing (FWM) beams can be the compensated to form spatial solitons during their propagations. When multiple laser beams are involved, the spatial patterns can be quite complicated depending on their beam overlaps, frequency detunings, atomic density, and relative intensities. Various novel soliton patterns can appear in different parametric regions for the probe and the generated FWM beams, making the multi-level atomic systems good playground to investigate novel types of solitons, such as gap, dipole, and vortex solitons. Due to the easy access of experimental parameters in the multi-level EIT system, the soiton patterns can be easily controlled, so the transition from one type of solion pattern to another can be experimentally observed. Such easy controllability provides a platform for comparisons between theoratical models and experimental observations. Controlling spatial solitons can find important applications in imaging storage, processing, and communication.