Strong terahertz radiation generation by beating of two spatial-triangular beams in collisional magnetized plasma

Abstract

A scheme of terahertz (THz) radiation generation is proposed by beating of two spatial-triangular laser beams in plasma with a spatially periodic density when electron–neutral collisions have taken into account. In this process, the laser beams exert a ponderomotive force on the electrons of the plasma and impart the oscillatory velocity at the difference frequency in the presence of a static magnetic field which is applied parallel to the direction of the lasers. We show that higher efficiency and stronger THz radiation are achieved when the parallel magnetic field is used to compare the perpendicular magnetic field. The effects of beam width of lasers, collision frequency, periodicity of density ripples, and magnetic field strength are analyzed for strong THz radiation generation. The THz field of the emitted radiations is found to be highly sensitive to collision frequency and magnetic field strength. In this scheme with the optimization of plasma parameters, the efficiency of order 21% is achieved.

Terahertz wave excitation by nonlinear coupling of intense laser field with magnetized plasma

“…Motivating the ponderomotive nonlinearity, Sharma et al [13] have obtain terahertz in gigawatt range by increasing the external longitudinal magnetic field. A. Hematizadeh et al [14] have propose a scheme to generate terahertz wave by beating of two laser beams inside plasma with a spatially periodic density taken into account the electron-neutral collisions. Munther et.…”

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.…”

“…[64] Malik et al have introduced a mechanism of efficient and highly focused THz radiation generation by photo-mixing top-hat-like lasers in a rippled density plasma in the presence of a transverse static magnetic field. [69][70][71] In this paper, we have proposed a scheme for THz radiation in the presence of a magnetic field, which is applied obliquely to the laser beams' direction; moreover, the general formulas for efficiency and THz field amplitude with arbitrary laser beam profiles have been derived. [66] Varshney et al have proposed THz radiation by beating of two cosh-Gaussian lasers in a rippled density plasma in the presence of a transverse static magnetic field.…”

“…[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.…”

“…A parallel magnetic field is applied to the laser beams' direction in references. [69][70][71] In this paper, we have proposed a scheme for THz radiation in the presence of a magnetic field, which is applied obliquely to the laser beams' direction; moreover, the general formulas for efficiency and THz field amplitude with arbitrary laser beam profiles have been derived. These formulas can be used for any beam profile.…”