Terahertz radiation generation via beating of Hermite-Cosh-Gaussian laser beams in a plasma: effect of tapered wiggler magnetic field

The study investigates the generation of terahertz radiation by two Hermite-Cosh-Gaussian laser beams in collisionless magnetized plasma in a tapered magnetic field. A tapered wiggler magnetic field is applied perpendicular to the propagation direction of the beams. The externally applied magnetic field produces Lorentz force, which alters the dynamics of the oscillating electrons, leading to modifications in the plasma wave. The force generates nonlinear velocity and nonlinear current density within the plasma, resulting in efficient Terahertz generation. The study analyzes the effect of normalized transverse distance, tapering parameter, cyclotron frequency, plasma frequency, and other laser parameters such as Hermite polynomial mode index (m) and decentered parameter on the terahertz conversion efficiency. The results show that the terahertz amplitude significantly increases with wiggler magnetic field strength, mode index, decentered parameter, and laser intensity and decreases with tapering parameter. The innovative approach demonstrates practicality in creating powerful, customizable, and energy-efficient terahertz radiation sources by optimizing the values of the decentered parameter and Hermite polynomial mode index. Also, the plasma wiggler approach provides a promising avenue for generating high-energy, tunable terahertz waves.