Nonlinear responses of inhomogeneous collisional plasma to pondermotive effect in the laser- plasma interaction

The pondermotive force causes interesting nonlinear processes in the interaction of the intense laser beamwith plasma. The pondermotive effect modifies the profile density, and in turn, affects the propagation ofthe laser beam through the plasma medium. Here, it is considered the inhomogeneous collisional plasma,and assumed that a high-intensity laser beam passes through the plasma. The nonlinear electric fieldsolutions are obtained by applying numerical methods. Due to the nonlinear ponderomotive force, thechanges in the physical characteristics of the electromagnetic wave are investigated. The wave profile oflaser beam and the initial electron density have an important effect on the passing of the electromagneticfield through the plasma. Here, the Gaussian and the plane wave for the wave profile and the Gaussian andlinear profiles for the initial electron density are considered. The obtained numerical results show that theprofile of the incident wave and also the initial electron density have significant effects on the laser-plasmainteraction. It is also demonstrated that the wave profile of laser beam incident to the inhomogeneousplasma plays an important role in its absorption by the plasma