Self-focusing of cosh-Gaussian laser beams in a parabolic medium with linear absorption

AbstractIn this paper, self-focusing of finite Airy–Gaussian (AiG) laser beams in collisionless plasma has been investigated. The source of nonlinearity considered herein is relativistic. Based on the Wentzel–Kramers–Brillouin (WKB) and paraxial-ray approximations, the nonlinear coupled differential equations for beam-width parameters in transverse dimensions of AiG beams have been established. The effect of beam's modulation parameter and linear absorption coefficient on the self-focusing/defocusing of the beams is specifically considered. It is found that self-focusing/defocusing of finite AiG beams depends on the range of modulation parameter. The extent of self-focusing is found to decrease with increase in absorption.

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Relativistic self-focusing of finite Airy-Gaussian laser beams in cold quantum plasma

Journal of Optics ◽

10.1007/s12596-021-00718-7 ◽

2021 ◽

Author(s):

V. S. Pawar ◽

P. P. Nikam ◽

S. R. Kokare ◽

S. D. Patil ◽

M. V. Takale

Keyword(s):

Laser Beams ◽

Quantum Plasma ◽

Self Focusing

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Self-Focusing of Laser Beams and Stimulated Raman Gain in Liquids

Physical Review Letters ◽

10.1103/physrevlett.15.1010 ◽

1965 ◽

Vol 15 (26) ◽

pp. 1010-1012 ◽

Cited By ~ 144

Author(s):

P. Lallemand ◽

N. Bloembergen

Keyword(s):

Laser Beams ◽

Raman Gain ◽

Self Focusing ◽

Stimulated Raman

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Relativistic self-focusing of a rippled laser beam in a plasma

Journal of Plasma Physics ◽

10.1017/s0022377899008016 ◽

1999 ◽

Vol 62 (4) ◽

pp. 389-396 ◽

Cited By ~ 10

Author(s):

M. V. ASTHANA ◽

A. GIULIETTI ◽

DINESH VARSHNEY ◽

M. S. SODHA

Keyword(s):

Refractive Index ◽

Laser Beam ◽

The Self ◽

Laser Beams ◽

Radial Dependence ◽

Main Beam ◽

Gaussian Laser Beam ◽

Self Focusing ◽

Saturation Effects ◽

Paraxial Ray

This paper presents an analysis of the relativistic self-focusing of a rippled Gaussian laser beam in a plasma. Considering the nonlinearity as arising owing to relativistic variation of mass, and following the WKB and paraxial-ray approximations, the phenomenon of self-focusing of rippled laser beams is studied for arbitrary magnitude of nonlinearity. Pandey et al. [Phys. Fluids82, 1221 (1990)] have shown that a small ripple on the axis of the main beam grows very rapidly with distance of propagation as compared with the self-focusing of the main beam. Based on this analogy, we have analysed relativistic self-focusing of rippled beams in plasmas. The relativistic intensities with saturation effects of nonlinearity allow the nonlinear refractive index in the paraxial regime to have a slower radial dependence, and thus the ripple extracts relatively less energy from its neighbourhood.

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Self-Focusing of Hermite-Cosh-Gaussian Laser Beams in Plasma under Density Transition

Advances in Optics ◽

10.1155/2014/942750 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 8

Author(s):

Manzoor Ahmad Wani ◽

Niti Kant

Keyword(s):

Laser Beam ◽

Plasma Density ◽

Focal Spot ◽

Beam Width ◽

Spot Size ◽

Laser Beams ◽

Equation Approach ◽

Focal Spot Size ◽

Self Focusing ◽

Small Spot

Self-focusing of Hermite-Cosh-Gaussian (HChG) laser beam in plasma under density transition has been discussed here. The field distribution in the medium is expressed in terms of beam-width parameters and decentered parameter. The differential equations for the beam-width parameters are established by a parabolic wave equation approach under paraxial approximation. To overcome the defocusing, localized upward plasma density ramp is considered, so that the laser beam is focused on a small spot size. Plasma density ramp plays an important role in reducing the defocusing effect and maintaining the focal spot size up to several Rayleigh lengths. To discuss the nature of self-focusing, the behaviour of beam-width parameters with dimensionless distance of propagation for various values of decentered parameters is examined by numerical estimates. The results are presented graphically and the effect of plasma density ramp and decentered parameter on self-focusing of the beams has been discussed.

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