Optical control of an Airy beam via four-wave mixing and six-wave mixing.

Abstract

We use a conventional linear Airy beam to prepare a nonlinear Airy beam via four-wave mixing (FWM) and six-wave mixing (SWM) processes in an atomic vapor. We find that its ballistic trajectory is a result of the competition between the transverse self-acceleration and nonlinear phase shift, and the intensity of Airy beam's sub lobes or main lobe is suppressed due to destructive interference of the FWM and SWM processes. By controlling the nonlinear overlap area of the linear Airy beam and two Gaussian beams, we find that the Airy beam's profile varies from one-dimensional (1D) to two-dimensional (2D). The profile evolution process can be applied to create a new (to our knowledge) type of nonlinear filter. In addition, we also observe the Airy beam's pattern in momentum space with electromagnetically induced transparency (EIT) in an atomic vapor. Our research results open up new possibilities for manipulating Airy beams that cannot be achieved with a conventional Airy beam.