Influence of rippled density and laser profile on third harmonic generation using cosh‐Gaussian laser pulses in inhomogeneous magnetized plasmas

The third harmonic generation of cosh‐Gaussian laser pulses in inhomogeneous magnetized plasmas is investigated. The plasma is considered inhomogeneous with a sinusoidal form, and the external magnetic field has an oscillating wiggler structure. Various ponderomotive forces are obtained considering the external magnetic field, the magnetic field of the laser beam, and different orders of electron velocity. These forces are nonlinear, which leads to a nonlinear current density. Using linear and nonlinear current densities and Maxwell's equations, the wave equation of the third harmonic wave is obtained. Results show that by increasing the deviation parameter from the center and the external magnetic field, the third harmonic electric field increases. It is also indicated that by increasing the laser beam width, the excited electric field decreases. Finally, it is found that by increasing the wavenumber and amplitude of the rippled electron density, the amplitude of the third harmonic electric field increases.