Self-focusing of intense laser beam in magnetized plasma

Abstract

In this paper, evolution of spot size of an intense laser beam in cold, underdense, magnetized plasma has been studied. The plasma is embedded in a uniform magnetic field perpendicular to both, the direction of propagation and electric vector of the radiation field. Nonlinear current density is set up and the source dependent expansion method is used to determine the evolution of the spot size of a laser beam having a Gaussian profile. It is shown that transverse magnetization of plasma enhances the self-focusing property of the laser beam leading to reduction in critical power required to self-focus the beam.

Additional focusing of a high-intensity laser beam in a plasma with a density ramp and a magnetic field

“…Therefore, selffocusing of a high-intensity laser beam in a plasma is a very important research issue nowadays. [8][9][10][11][12][13][14] The experimental results on relativistic self-focusing in hydrogen gas have been reported by Fedosejevs et al 15 Hafizi et al 16 studied the propagation of an intense laser beam in a plasma, including the relativistic and ponderomotive effects. Their results show that the laser beam can acquire a minimum spot size due to the relativistic self-focusing in a plasma.…”

Self-focusing of laser pulse propagating in magnetized plasma

“…tÞ exp½iðk 0 z À o 0 tÞb e y þ c:c: Expanding the relevant perturbation quantities in orders of radiation field [7] to the third order and then separating into three equations according to their orders, one can obtain equations with the first-order terms…”

“…The interaction between laser pulse and plasma would also become more complex in the outside magnetic field, and the nonlinear terms, such as ponderomotive force, are all affected, which result in changes in self-focusing and filament. Jha et al [7,8] had studied the self-focusing in magnetized plasma in which the outside magnetic field was set in special aspect (along the y-or z-axis). Based on former works, we introduce outside magnetic field in normal aspect in these studies.…”

Self-focusing of a high-intensity laser pulse by a magnetized plasma lens in sub-relativistic regime

“…Although some methods have been already studied to obtain the variations of laser spot size with plasma distance such as SDE (source dependence expansion) [35,36], but these methods present only the variation of laser spot size with distance. In the present method (Lagrangian density), as we see, other parameters such as the variation of laser spot size with the variations of the plasma distance and the external magnetic field for right and left-handed circular polarizations are obtained.…”

“…We can use these mentioned techniques to study the nonlinear relativistic self-focusing phenomena with taking into account the relativistic mass corrections. Relativistic self-focusing is caused by the mass increase of the electrons traveling at speed and approaching the speed of light which modifies the plasma refractive index [4,6,[30][31][32][33][34][35][36][37][38]. As we know, the propagation of a laser beam without diffraction is an essential factor to get better application [39].…”