scholarly journals Self-Focusing Property of Partially Coherent Beam With Non-Uniform Correlation Structure in Non-Linear Media

2022 ◽  
Vol 9 ◽  
Author(s):  
Lu Lu ◽  
Zhiqiang Wang ◽  
Jiayi Yu ◽  
Chunhong Qiao ◽  
Rong Lin ◽  
...  
Keyword(s):  
Beam Width ◽  
Vital Role ◽  
Coherent Beam ◽  
The Self ◽  
Correlation Structure ◽  
Threshold Condition ◽  
Partially Coherent ◽  
Self Focusing ◽  
Non Linear ◽  
Focusing Property

Coherence in a light beam has the potential to serve as a degree of freedom for manipulating the beam. In this work, the self-focusing property of a partially coherent beam with a non-uniform correlation structure propagating in a non-linear medium is investigated. The analysis of the evolution of beam width reveals that the coherence structure plays a vital role in the self-focusing formation. A threshold condition for the coherence radius is proposed for the first time, and the relation of self-focusing length and initial coherence radius is studied numerically and analytically. It is shown that a feasible approach for manipulating the self-focusing length by adjusting the initial coherence radius is achieved.

Combined influence of axial electron temperature and exponential plasma density ramp on the self-focusing of a chirped laser in plasma

2020 ◽  
Vol 75 (7) ◽  
pp. 671-675
Author(s):  
Niti Kant ◽  
Vishal Thakur
Keyword(s):  
Electron Temperature ◽  
Pulse Laser ◽  
Plasma Density ◽  
Beam Width ◽  
Spot Size ◽  
Higher Order ◽  
The Self ◽  
Chirped Pulse ◽  
Self Focusing ◽  
Paraxial Ray

AbstractAn analysis of the self-focusing of highly intense chirped pulse laser under exponential plasma density ramp with higher order value of axial electron temperature has been done. Beam width parameter is derived by using paraxial ray approximation and then solved numerically. It is seen that self-focusing of chirped pulse laser is intensely affected by the higher order values of axial electron temperature. Further, influence of exponential plasma density ramp is studied and it is concluded that self-focusing of laser enhances and occurs earlier. On the other hand defocusing of beam reduces to the great extent. It is noticed that the laser spot size reduces significantly under joint influence of the density ramp and the axial electron temperature. Present analysis may be useful for the analysis of quantum dots, the laser induced fusion and etc.

QUASIPERIODIC ROUTE TO SPATIOTEMPORAL CHAOS IN A NONLINEAR SCHRÖDINGER EQUATION WITH THE SATURABLE NONLINEARITY

1994 ◽  
Vol 08 (24) ◽  
pp. 1511-1516
Author(s):  
CANGTAO ZHOU
Keyword(s):  
Hamiltonian System ◽  
Schrödinger Equation ◽  
Coherent Structures ◽  
Schrodinger Equation ◽  
Spatiotemporal Chaos ◽  
Nonlinear Schrodinger Equation ◽  
The Self ◽  
Saturable Nonlinearity ◽  
Self Focusing ◽  
Non Linear

The route from the coherent structures to the spatiotemporal complicated patterns is numerically investigated in terms of a continuum Hamiltonian system, that is, the non-linear Schrödinger equation with the self-focusing nonlinearity, where the quasiperiodic route is first observed.

scholarly journals Correlation-induced self-focusing and self-shaping effect of a partially coherent beam

2016 ◽  
Vol 4 ◽  
Author(s):  
Yahong Chen ◽  
Yangjian Cai
Keyword(s):  
Correlation Function ◽  
Intensity Distribution ◽  
High Power ◽  
Thermal Processing ◽  
Coherent Beam ◽  
The Other ◽  
Model Function ◽  
Partially Coherent ◽  
Self Focusing ◽  
Propagation Properties

A new specially correlated partially coherent beam named nonuniform multi-Gaussian correlated (NMGC) partially coherent beam is introduced. The correlation functions of such beam in $x$ and $y$ directions are different from each other, i.e., nonuniform correlation function in one direction and multi-Gaussian correlated Schell-model function in the other direction. The propagation properties of an NMGC partially coherent beam in free pace are demonstrated, and we find that the intensity distribution of such beam exhibits self-focusing and self-shifting effect in one direction and self-shaping effect in the other direction on propagation. The correlation-induced self-focusing and self-shaping effect will be useful in some applications, where the high power and shaped laser is required, such as material thermal processing and laser carving.

scholarly journals Focusing of Hermite-cosh-Gaussian laser beams in collisionless magnetoplasma

2010 ◽  
Vol 28 (2) ◽  
pp. 343-349 ◽  
Author(s):  
S.D. Patil ◽  
M.V. Takale ◽  
S.T. Navare ◽  
M.B. Dongare
Keyword(s):  
Beam Width ◽  
The Self ◽  
Laser Beams ◽  
Combined Effects ◽  
Dimensionless Distance ◽  
Self Focusing ◽  
Mode Index ◽  
Ponderomotive Nonlinearity

AbstractThis paper presents an investigation of the focusing of Hermite-cosh-Gaussian laser beams in magneto-plasma by considering ponderomotive nonlinearity. The dynamics of the combined effects of nonlinearity and spatial diffraction is presented. To highlight the nature of focusing, plot of beam-width parameter vs. dimensionless distance of propagation has been obtained. The effect of mode index and decentered parameter on the self-focusing of the beams has been discussed.

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.

scholarly journals Relativistic and ponderomotive self-focusing of a laser pulse in magnetized plasma

2012 ◽  
Vol 30 (4) ◽  
pp. 659-664 ◽  
Author(s):  
Anamika Sharma ◽  
V.K. Tripathi
Keyword(s):  
Laser Pulse ◽  
Cyclotron Frequency ◽  
Ponderomotive Force ◽  
Beam Width ◽  
Laser Frequency ◽  
Electron Cyclotron ◽  
The Self ◽  
Magnetized Plasma ◽  
Electron Cyclotron Frequency ◽  
Self Focusing

AbstractThe self-focusing of an intense right circularly polarized Gaussian laser pulse in magnetized plasma is studied. The ions are taken to be immobile and relativistic mass effect is incorporated in both the plasma frequency (ωp) and the electron cyclotron frequency (ωc) while determining the ponderomotive force on electrons. The ponderomotive force causes electron expulsion when the effective electron cyclotron frequency is below twice the laser frequency. The nonlinear plasma dielectric function due to ponderomotive and relativistic effects is derived, which is then employed in beam-width parameter equation to study the self-focusing of the laser beam. From this, we estimate the importance of relativistic self-focusing in comparison with ponderomotive self-focusing at moderate laser intensities. The beam width parameter decreases with magnetic field indicating better self-focusing. When the laser intensity is very high, the relativistic gamma factor can be modeled as ${\rm \gamma} = 0.8\left({{{{\rm \omega} _c } / {\rm \omega} }} \right)+ \sqrt {1 + a_0^2 }$γ=0.8(ωc/ω)+1+a02 where ω and a0 are the laser frequency and the normalized laser field strength, respectively. The cyclotron effects on the self-focusing of laser pulse are reduced at high field strengths.

scholarly journals Sensitiveness of light absorption for self-focusing at laser–plasma interaction with weakly relativistic and ponderomotive regime

2016 ◽  
Vol 34 (4) ◽  
pp. 669-674 ◽  
Author(s):  
S.D. Patil ◽  
M.V. Takale ◽  
V.J. Fulari ◽  
T.S. Gill
Keyword(s):  
Laser Beam ◽  
Light Absorption ◽  
Beam Width ◽  
Vital Role ◽  
Equation Approach ◽  
Gaussian Laser Beam ◽  
Laser Plasma Interaction ◽  
Self Focusing ◽  
Plasma Density Distribution ◽  
Relativistic Regime

AbstractIn the present paper, we have examined the sensitiveness of light absorption for self-focusing of Gaussian laser beam in plasma. By introducing dielectric function of plasma under ponderomotive and weakly relativistic regime, we have established the differential equation for beam-width parameter by using parabolic equation approach under Wentzel-Kramers-Brillouin and paraxial approximations and solved it numerically. In order to incorporate the sensitiveness of light absorption for self-focusing, behavior of normalized beam-width parameter; plasma density distribution with dimensionless distance of propagation is presented graphically and discussed. Numerical analysis shows that light absorption plays a vital role in self-focusing of laser beam in plasma under weakly relativistic and ponderomotive regime and gives reasonably interesting results.

The Propagation Properties of a Laguerre–Gaussian Beam in Nonlinear Plasma

2021 ◽  
Author(s):  
Suo Qiangbo ◽  
Yiping Han ◽  
Zhiwei Cui
Keyword(s):  
Gaussian Beam ◽  
Order Differential Equation ◽  
Plasma Temperature ◽  
Beam Width ◽  
The Self ◽  
Nonlinear Plasma ◽  
Vortex Charge ◽  
Self Focusing ◽  
Propagation Properties ◽  
Focusing Properties

Abstract The self-focusing properties of the Laguerre-Gaussian (LG) beam in nonlinear plasma, characterized by significant collisional or ponderomotive nonlinearity have been explored. The second-order differential equation of the beam width is established from Maxwell’s equations with Wentzel–Kramers–Brillouin (WKB) and paraxial like approximation. The effect of the vortex charge number, intensity parameter and plasma temperature on the self-focusing properties of the Laguerre-Gaussian beam has been investigated.

scholarly journals Stability and dynamics of a cosh-Gaussian laser beam in relativistic thermal quantum plasma

2018 ◽  
Vol 36 (3) ◽  
pp. 341-352 ◽  
Author(s):  
Ranju Mahajan ◽  
Richa ◽  
Tarsem Singh Gill ◽  
Ravinder Kaur ◽  
Munish Aggarwal
Keyword(s):  
Laser Beam ◽  
Phase Modulation ◽  
Variational Approach ◽  
Significant Contribution ◽  
Vital Role ◽  
The Self ◽  
Quantum Plasma ◽  
Propagation Characteristics ◽  
Gaussian Laser Beam ◽  
Self Focusing

AbstractThis paper presents an investigation on the self-focusing of a cosh-Gaussian laser beam in the thermal quantum plasma (TQP) by taking into account the effects of relativistic nonlinearity. An appropriate nonlinear Schrödinger equation has been solved analytically by applying the variational approach. The self-focusing and the self-phase modulation are examined under a variety of parameters. The self-trapping of a cosh-Gaussian laser beam is further studied at various values of the decentered parameter, b with different absorption levels, ${k}^{\prime}_i$. Numerical analysis shows that these parameters play a vital role in propagation characteristics. The significant contribution of the quantum effects to enhance the self-focusing and minimize the longitudinal phase has been observed. Further, a comparison has been made with the classical relativistic (CR), the relativistic cold quantum (RCQ), and the thermal quantum (TQ) regimes. The self-focusing is found to occur earlier and is strongest for the case of TQP in the present analysis.

scholarly journals A Mathematical Modelling with Zakharov System for Langmuir Wave in Unmagnetized Plasma

2020 ◽  
Vol 3 (11) ◽  
pp. 134-136
Author(s):  
Sudarshan Kumar Chakravarti
Keyword(s):  
Ponderomotive Force ◽  
Langmuir Wave ◽  
Vital Role ◽  
The Self ◽  
Beam Radius ◽  
Zakharov System ◽  
Focusing Effect ◽  
Relativistic Mass ◽  
Self Focusing ◽  
Unmagnetized Plasma

In this article we present a discussion and overview of mathematical result of the self-focusing of a Langmuir wave which governs Zakharov system and has studied the self- focusing of a Langmuir wave following by Gaussian distribution. Langmuir wave propagates through uncharged plasma which governed by Zakharov systems. The phenomenon plays a vital role in the Dynamics. We present the article mathematical model with effect of Landou damping. Relativistic mass oscillation and ponderomotive force on electrons of the ionized plasma encouraged the Langmuir wave which resists the self-focusing effect when damping is ignored. The Beam radius gets narrow. when it further propagates considering the paraxial ray’s approximation, the self-focusing length Rn. It shows that characteristics of varying bandwidth distance of propagation in relativistic plasma.

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