Self-focusing of Gaussian laser beam in weakly relativistic and ponderomotive regime using upward ramp of plasma density

Abstract

We have studied the steady state self-focusing of Gaussian laser beam in weakly relativistic and ponderomotive regime for upward increasing plasma ramp density profile. We have obtained the differential equation for beam width parameter by using parabolic equation approach under the usual Wentzel–Kramers–Brillouin and paraxial approximations. The variation of beam width parameter with respect to dimensionless distance of propagation is presented graphically by varying the parameters of density profile, intensity parameter, and electronic temperature. It shows that the above stated parameters play an important role in propagation characteristics and give reasonably interesting results.