Resonant beat wave excitation of terahertz radiation in a magnetized plasma channel

Abstract

The nonlinear mixing of two Gaussian laser beams in a magnetized plasma channel to excite a difference frequency terahertz (THz) radiation is investigated. The beat frequency ponderomotive force imparts an oscillatory velocity to electrons that couples with the pre-existing density ripple to produce a nonlinear current driving the THz radiation. The density ripple provides phase synchronism while the axial magnetic field enhances the nonlinear coupling through cyclotron resonance. The THz power scales with the square of density ripple amplitude and inversely with the square of laser frequencies.

Nonlinear Propagation of Gaussian Laser Beam in Magnetized Plasma: Effect of Oblique Magnetic Field

“…The different intensity profiles of laser beams are also important in their propagation through plasmas [4]. It is well known that by applying external magnetic field, self-focusing of the laser beam propagating through plasma can be changed, which have wide range of applications such as harmonic generation [5,6], laser wakefield acceleration [7,8], generation of THz radiation [9,10], etc.…”

Self-Focusing of Gaussian Laser Beam in an Axially Magnetized Plasma

“…When a constant external magnetic field is applied to the plasma, it affects the self-focusing of laser beams [5]. Such magnetization of plasma leads to wide-ranging applications such as harmonic generation [6,7], laser wakefield acceleration [8,9], generation of THz radiation [10], etc.…”

Terahertz radiation generation by beating of two chirped laser pulses in a warm collisional magnetized plasma

“…The presence of an external magnetic field perpendicular to the direction of laser pulse propagation could increase the radiation efficiency up to several times more than the absence of a magnetic field. [21][22][23][24][25][26] Since the resonance excitation depends on the tuning of pulse frequency and plasma density, the different types of plasma density, for example, the ripple density, is used to increase the terahertz radiation efficiency. [27][28][29] The terahertz generation by the beating of two Gaussian laser beams for periodically modulated density in the presence of a static magnetic field has been studied by Malik et al [14] Their analytical calculations show that the resonant excitation of THz under the mentioned conditions is quite effective.…”