Impact of Self-Focused Q-Gaussian Laser Beam on Second Harmonic Generation in Collisional Plasma

The present communication explores the impact of the self-focused q-Gaussian laser beam on the second harmonic generation (SHG) in collisional plasma. In the case of collisional plasma, the generation of density gradients takes place in a perpendicular direction due to carrier redistribution on account of nonuniform heating. Due to density gradients, electron plasma wave (EPW) is produced at pump beam frequency. EPW interacts with the pump beam, producing SHG. The well-known Wentzel–Kramers–Brillouin approximation and paraxial theory are used for deriving 2nd-order ODE for the beam waist of the main beam and the efficiency of the 2nd harmonic. A numerical solution of equations is carried out by using the supreme variables of laser and plasma. It is observed from analysis that the beam's focusing ability and the efficiency of the 2nd harmonic are enhanced with the increase in laser intensity, density of plasma electrons, radius of beam and q-values.