Nonlinear Beam Dynamics of q-Gaussian Laser Beams in Absorptive Thermal Quantum Plasma: Relativistic and Ponderomotive Nonlinearities

The current study examines nonlinear beam dynamics of q-Gaussian laser beams propagating through absorptive thermal quantum plasma considering relativistic-ponderomotive nonlinear effects. There is energy dissipation along propagation distance due to linear absorption, thereby causing distance dependent nonlinear response. By making use of quasi-optical approach along with WKB and paraxial approximations, a modified 2nd order propagation equation governing the evolution of beam width is obtained. Numerical simulations are then conducted for exploring influence of key parameters, including absorption coefficient, laser intensity, plasma density, initial beam radius, q-parameter, and Fermi temperature on beam propagation. The outcome clearly shows that relativistic-ponderomotive nonlinear effects greatly enhance nonlinear focusing, whereas absorption counteracts this effect by reducing beam compression and shifting the focal position. A comparative study with both cold quantum and classical relativistic plasma models highlights the essential contribution of quantum effects to laser propagation through dense plasmas.