Resonant third harmonic generation of super-Gaussian laser beam in a rippled density plasma

Resonant third harmonic generation of super-Gaussian laser beam in rippled density plasma is studied. Both the relativistic and ponderomotive nonlinearities are included in the analysis, and the study is done for self-guided laser beam. The quasi-static component of ponderomotive force creates electron density depression in the beam region while the second harmonic component leads to second harmonic density oscillations, leading to third harmonic generation. The relativistic mass variation supplements these processes with same order of contributions. The ripple provides the phase matching and requisite ripple wave number decreases with the frequency of the laser.