Ponderomotive interaction of high-power cylindrical vector beams with plasma

Abstract

The spatio-temporal evolution of the interaction of a high-power cylindrical vector (CV) beam with plasma is investigated numerically using the finite-difference time-domain (FDTD) method. According to the theory of ponderomotive nonlinearity of plasma, the Drude model with both modified plasma frequency and modified collision frequency is given for depicting the dispersive and dissipative permittivity of plasma with the presence of a high-power laser. The corresponding algorithms of the FDTD method are proposed for numerically simulating the nonlinear dielectric model and for artificially generating the radially and azimuthally polarized CV beams. The simulation results about the 3D dynamic interaction processes between the high-power CV beams and plasma are presented and discussed, by which we find that the plasma has different modulation effects on the two types of CV beams with different polarization states. The anticipated phenomena, such as the self-focusing of a high-power laser beam in plasma and the self-tunneling of plasma, are also verified. This study provides a transient and dynamic simulation method for laser–plasma interaction and also exploits a new approach for the field modulation of laser beams by plasma.