Effect of laser intensity redistribution on terahertz field generation via laser wakefield in a magnetized plasma

The wakefield excitation in a plasma is very sensitive to the laser intensity distribution, which may further affect the plasma current generation. In this direction, we investigate the effect of laser intensity redistribution on wakefield-induced THz field generation in a magnetized plasma. Laser pulse induces wakefield by the charge separation in a plasma, having both the axial and transverse components. Axial component of wakefield accelerates the electrons and transverse field component propagates and radiates at plasma vacuum boundary. We here consider different laser intensity profiles to excite laser wakefield and consequent terahertz fields. Field decentered parameter (b) is introduced in laser field profile that allows the redistribution of laser intensity. The intensity gradient force changes due to the effect of laser intensity redistribution that further affects the terahertz field significantly. The spectral analysis shows the terahertz field in the range of 19-20 THz and the peak value of the generated terahertz field is enhanced significantly for Hollow-Gaussian laser intensity distribution.