Terahertz wave generation by nonlinear mixing of lasers in a finite overdense plasma slab

A method of generating THz radiation by nonlinear mixing of lasers obliquely incident on a finite slab of overdense plasma is formulated analytically. The incoming laser beam exerted a ponderomotive force on free electrons, which started oscillating at a frequency equal to the frequency difference of two laser beams. This results in a nonlinear current leading to THz radiation generation at the reflection as well as at the transmission side of the plasma slab. We have seen the effect of incident angle on the amplitudes of reflected and transmitted amplitudes of generated THz radiation. It is observed that the thickness of the slab and plasma density are the contributing parameters for the intensity of THz radiation generation.