ABSTRACT
In this chapter, we present a mechanism of THz radiation generation by excitation of nonlinear currents due to two flat top laser pulses of same 386intensities but different frequencies and wavenumbers in a plasma of modulated density. In this process, the ponderomotive force is developed, which leads to nonlinear current density that resonantly excites the radiation in the THz frequency range. The effect of beam width and density ripples is discussed for these currents and THz generation and comparative studies are made for flat top beams with Gaussian one.
