Self-focusing and cross-focusing of Gaussian electromagnetic beams in fully ionized collisional magnetoplasmas

Sodha, M. S.; Mishra, S. K.; Agarwal, Samarth

doi:10.1063/1.2801713

Cited by 37 publications

(17 citation statements)

References 50 publications

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“…Ren et al 7 studied the nonlinear interaction between light beams in a plasma showing that when two laser beams are coherent, the force can be repulsive or attractive, depending on their relative phase. Sodha et al 8 presented an analysis of cross-focusing of two coaxial beams in fully ionized magnetoplasma, taking into account the Ohmic heating of the electrons by the beams and loss of energy by electrons due to collision with the ions and electronic thermal conduction. Gupta et al 9 presented the cross focusing of two high power laser beams in a plasma under the effect of relativistic and ponderomotive nonlinearities.…”

Section: Introductionmentioning

confidence: 99%

Self focusing of a quadruple Gaussian laser beam in a plasma

2012

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The self focusing of a quadruple Gaussian laser beam, comprising four coherent identical Gaussian beams with axes parallel to ẑ but shifted from z-axis by −x0x̂,x0x̂,−x0ŷ,x0ŷ in a collisionless plasma, is investigated in the paraxial ray approximation. The nonlinearity arises through the ponderomotive force led plasma density redistribution. As the beam propagates, it maintains the shape of its intensity profile with spot size r0 of each of the four distributions modified from r0 to r0f, x0, modified to x0f and the axial intensity enhanced by 1/f2, where f is the beam width parameter. In the regime of quadratic nonlinearity, the threshold beam power for self focusing, Pth, increases with x0 as the laser intensity gradient decreases and the ponderomotive force becomes weaker. At beam power greater than Pth, the beam focuses in an oscillatory manner, i.e., f varies periodically with z due to the saturating effect of nonlinearity. The locations of intensity maxima of the four beams also vary periodically with z. As x0 increases from 0 to 0.6r0, the transverse intensity gradient becomes weaker and the rate of self focusing, i.e., the rate of variation of f with z decreases.

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Section: Introductionmentioning

confidence: 99%

Self focusing of a quadruple Gaussian laser beam in a plasma

2012

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“…(19)- (22), and the defined variables a, b, and c, we obtain the following equations, respectively, from Eqs. (14), (15), (17), and (19):…”

Section: Discussionmentioning

confidence: 99%

“…Ponderomotive force is a nonlinear force that a charged particle experiences in an inhomogeneous oscillatory electromagnetic field, reforming the plasma electron density distribution and effective dielectric constant of medium, which has been extensively considered in ultraintense standing wave propagation, nonisothermal plasma, magnetoplasma, co-axial electromagnetic wave propagation, and ring ripple formation. [14][15][16][17][18][19][20] Malik and Aria presented the spatial electron density distribution in the microwave and plasma interaction for different electron temperatures, and they regarded the electrons equilibrated by ponderomotive force and plasma pressure gradient force as the starting point. 21 Drude model was first proposed by Paul and Drude in 1900 to explain the transport properties of electrons in materials.…”

Section: Introductionmentioning

confidence: 99%

Propagation of Gaussian laser beam in cold plasma of Drude model

et al. 2011

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The propagation characters of Gaussian laser beam in plasmas of Drude model have been investigated by complex eikonal function assumption. The dielectric constant of Drude model is representative and applicable in describing the cold unmagnetized plasmas. The dynamics of ponderomotive nonlinearity, spatial diffraction, and collision attenuation is considered. The derived coupling equations determine the variations of laser beam and irradiation attenuation. The modified laser beam-width parameter F, the dimensionless axis irradiation intensity I, and the spatial electron density distribution n/n0 have been studied in connection with collision frequency, initial laser intensity and beam-width, and electron temperature of plasma. The variations of laser beam and plasma density due to different selections of parameters are reasonably explained, and results indicate the feasible modification of the propagating characters of laser beam in plasmas, which possesses significance to fast ignition, extended propagation, and other applications.

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“…Crossfocusing and mutual focusing/defocusing of multiple beams in magnetoplasma have been studied extensively by various researchers for the past few years. Sodha et al [23] have analyzed the cross-focusing of multiple coaxial beams in fully ionized magnetoplasma, taking into account the ohmic heating of the electrons by the beams and loss of energy by electrons due to collision with the ions and electronic thermal conduction. The cross-focusing of coaxial electromagnetic beams in a magnetoplasma, on account of the pondermotive force has been studied thoroughly by Sodha et al [24].…”

Section: Introductionmentioning

confidence: 99%