Strong terahertz radiation generation by beating of two laser beams in magnetized overdense plasma

Abstract

Terahertz (THz) radiation generation by nonlinear mixing of two laser beams, obliquely incident on an overdense plasma is investigated. In an overdense plasma, the laser beams penetrate to only thin layer of a plasma surface and reflected. At this thin layer, the laser beams exert a ponderomotive force on the electrons of plasma and impart them oscillatory velocity at the different frequency of lasers. THz waves appear in the reflected component from the plasma surface. The amplitude of THz waves can be augmented by applying the magnetic field perpendicular to the direction of propagation of lasers. It is found that the field strength of the emitted THz radiations is sensitive to the angle of incident of the laser beams, beat frequency, and magnetic field strength. In this scheme, the magnetic field strength plays an important role for strong THz wave generation.

Generation of terahertz radiation via cosh‐Gaussian and top‐hat laser beams in a collisional magnetized plasma

“…[58,59] Frequency multipliers are used to fundamentally shift sub-THz electronic oscillations into the THz range. [68][69][70][71] Pereira et al have described harmonic generation in semiconductor superlattices by starting from non-equilibrium Green's function input to relaxation rate-type analytical approximations for the Boltzmann equation in which imperfections in the structure lead to asymmetric current flow and scattering processes under forward and reverse bias. [62,63] Another way to generate THz radiation is to use semiconductor superlattice.…”

“…[67] Hematizadeh et al have presented a scheme for THz generation based on the nonlinear mixing of two oblique incident laser beams on an over-dense magnetized plasma; they have also reported generation of THz radiation from under-dense plasma by taking advantage of right-hand circularly polarized (RCP) and left-hand circularly polarized (LCP) waves via different laser beam profiles. [68][69][70][71] Pereira et al have described harmonic generation in semiconductor superlattices by starting from non-equilibrium Green's function input to relaxation rate-type analytical approximations for the Boltzmann equation in which imperfections in the structure lead to asymmetric current flow and scattering processes under forward and reverse bias. They have demonstrated the potential of superlattice devices for gigahertz to THz applications at room temperature.…”