Twisted terahertz radiation generation using Laguerre-Gaussian laser pulse propagating in axially magnetized plasma

Abstract

We present analytical and simulation study of twisted terahertz (THz) radiation generation via propagation of a circularly polarized Laguerre Gaussian (LG) laser pulse in homogeneous plasma embedded in an axial magnetic field. Analytical formulation is based on perturbation technique and quasistatic approximation. Longitudinal and transverse wakefields generated via laser plasma interactions are evaluated using Lorentz force and Maxwells equations in the mildly nonlinear regime. It is observed that two linearly polarized twisted terahertz (THz) radiation beams are generated in mutually perpendicular planes. Superposition of the two beams result in a single linearly polarized twisted THz radiation beam with modified amplitude and polarization direction. Three dimensional (3D) particle in cell (PIC) simulations are performed for this configuration using FBPIC code. Graphical comparison of amplitude of the resultant THz beam obtained via analytical and simulation studies is presented.