Terahertz wave generation by beating of two spatial-Gaussian lasers in collisional plasma

This paper revisits the resonant excitation of terahertz (THz) radiation by beating of two spatial-Gaussian laser beams shaving different frequencies and wave numbers but the same electric fields, where the ponderomotive force in the transverse direction is resulted due to the beating and spatial variation of the field of lasers. Effect of the electron-neutral collision frequency on the THz wave generation in the collisional plasma has been discussed.