Self-focusing and defocusing of TEM0p Hermite–Gaussian laser beams in collisionless plasma

2009 ◽  
Vol 282 (15) ◽  
pp. 3157-3162 ◽  
Author(s):  
M.V. Takale ◽  
S.T. Navare ◽  
S.D. Patil ◽  
V.J. Fulari ◽  
M.B. Dongare
Keyword(s):  
Collisionless Plasma ◽  
Laser Beams ◽  
Self Focusing

scholarly journals Numerical programming of self-focusing at laser–plasma interaction

2000 ◽  
Vol 18 (1) ◽  
pp. 59-72 ◽  
Author(s):  
F. OSMAN ◽  
R. CASTILLO ◽  
H. HORA
Keyword(s):  
Collisionless Plasma ◽  
Relativistic Effects ◽  
Laser Beams ◽  
Moderate Intensity ◽  
Lateral Direction ◽  
Laser Plasma Interaction ◽  
Relativistic Mass ◽  
Self Focusing ◽  
Wide Range ◽  
Nonlinear Force

This paper presents an investigation into the behavior of a laser beam of finite diameter in plasma with respect to forces and optical properties, which lead to self-focusing of the beam. The transient setting of ponderomotive nonlinearity in a collisionless plasma has been studied, and consequently the self-focusing of the pulse, and the focusing of the plasma wave occurs. The description of a self-focusing mechanism of laser radiation in the plasma due to nonlinear forces acting on the plasma in the lateral direction, relative to the laser has been investigated in the nonrelativistic regime. The behavior of the laser beams in plasma, which is the domain of self-focusing at high or moderate intensity, is dominated by the nonlinear force. The investigation of self-focusing processes of laser beams in plasma results from the relativistic mass and energy dependency of the refractive index at high laser intensities. Here, the relativistic effects are considered to evaluate the relativistic self-focusing lengths for the Nd glass radiation, at different plasma densities of various laser intensities. A numerical program in c++ that incorporates both the ponderomotive force in self-focusing mechanism and relativistic effects has been developed to explore in depth self-focusing over a wide range of parameters.

scholarly journals Domains of modulation parameter in the interaction of finite Airy–Gaussian laser beams with plasma

2020 ◽  
Vol 38 (3) ◽  
pp. 204-210
Author(s):  
V. S. Pawar ◽  
S. R. Kokare ◽  
S. D. Patil ◽  
M. V. Takale
Keyword(s):  
Absorption Coefficient ◽  
Collisionless Plasma ◽  
Beam Width ◽  
The Self ◽  
Laser Beams ◽  
Linear Absorption Coefficient ◽  
Linear Absorption ◽  
Self Focusing ◽  
Modulation Parameter ◽  
Paraxial Ray

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.

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

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

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

1965 ◽  
Vol 15 (26) ◽  
pp. 1010-1012 ◽  
Author(s):  
P. Lallemand ◽  
N. Bloembergen
Keyword(s):  
Laser Beams ◽  
Raman Gain ◽  
Self Focusing ◽  
Stimulated Raman

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

1999 ◽  
Vol 62 (4) ◽  
pp. 389-396 ◽  
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.

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

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
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.

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

2009 ◽  
Vol 47 (5) ◽  
pp. 604-606 ◽  
Author(s):  
S.D. Patil ◽  
S.T. Navare ◽  
M.V. Takale ◽  
M.B. Dongare
Keyword(s):  
Laser Beams ◽  
Linear Absorption ◽  
Self Focusing
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