Effect of dust on an amplitude modulated electromagnetic beam in a plasma

A large amplitude modulated Gaussian electromagnetic beam propagating in a dusty plasma has been studied. The electrons are heated nonuniformly by the beam. For the nonsteady state, we obtain nonlinear current density in the presence of dust grains. This expression has been used to study the nonstationary self-focusing and resulting self-distortion of the amplitude modulated electromagnetic beam. It has been observed that the effect of dust is drastic on the modulation index in comparison to dust free plasma. A simple scaling showing the dependence of modulation index on dust grain size and charge has been presented.