scholarly journals Effects of plasma electron temperature and magnetic field on the propagation dynamics of Gaussian laser beam in weakly relativistic cold quantum plasma

2019 ◽  
Vol 37 (4) ◽  
pp. 435-441 ◽  
Author(s):  
Munish Aggarwal ◽  
Vimmy Goyal ◽  
Richa Kashyap ◽  
Harish Kumar ◽  
Tarsem Singh Gill
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Electron Temperature ◽  
Axial Magnetic Field ◽  
Beam Width ◽  
Plasma Electron ◽  
Quantum Plasma ◽  
Gaussian Laser Beam ◽  
Self Focusing ◽  
Initial Plasma

AbstractSelf-focusing of Gaussian laser beam has been investigated in quantum plasma under the effect of applied axial magnetic field. The nonlinear differential equation has been derived for studying the variations in the beam-width parameter. The effect of initial plasma electron temperature and the axial magnetic field on self-focusing and normalized intensity are studied. Our investigation reveals that normalized intensity increases to tenfolds where quantum effects are dominant. The normalized intensity further increases to twelvefolds on increasing the magnetic field.

scholarly journals Relativistic ponderomotive self-focusing of quadruple Gaussian laser beam in cold quantum plasma

2018 ◽  
Vol 36 (3) ◽  
pp. 353-358 ◽  
Author(s):  
Richa ◽  
Munish Aggarwal ◽  
Harish Kumar ◽  
Ranju Mahajan ◽  
Navdeep Singh Arora ◽  
...  
Keyword(s):  
Refractive Index ◽  
Laser Beam ◽  
Electron Temperature ◽  
Density Perturbation ◽  
Beam Width ◽  
Quantum Plasma ◽  
Gaussian Laser Beam ◽  
Self Focusing ◽  
Linear Differential ◽  
Paraxial Ray

AbstractIn the present paper, we have investigated self-focusing of the quadruple Gaussian laser beam in underdense cold quantum plasma. The non-linearity chosen is associated with the relativistic mass effect that arises due to quiver motion of electron and electron density perturbation caused by ponderomotive force. The non-linearity modifies the plasma frequency in the dielectric function and hence the refractive index of the medium. The focusing/defocusing of the quadruple laser depends on the refractive index of the medium. We have set up non-linear differential equation that controls the beam width parameter by using well-known paraxial ray approximation and Wentzel–Krammers–Brillouin approximation. The effect of intensity parameter and electron temperature is observed on laser beam self-focusing in the presence of cold quantum plasma. From the results, it is revealed that electron temperature and the initial intensity of the laser beam control the profile dynamics of the laser beam.

scholarly journals Combined effect of relativistic and ponderomotive nonlinearity on self-focusing of Gaussian laser beam in a cold quantum plasma

2016 ◽  
Vol 34 (3) ◽  
pp. 426-432 ◽  
Author(s):  
H. Kumar ◽  
M. Aggarwal ◽  
Richa ◽  
T.S. Gill
Keyword(s):  
Laser Beam ◽  
Beam Width ◽  
Combined Effect ◽  
Quantum Plasma ◽  
Gaussian Laser Beam ◽  
Relativistic Case ◽  
Self Focusing ◽  
Ponderomotive Nonlinearity ◽  
Paraxial Ray ◽  
The Impact

AbstractIn the present paper, we have investigated self-focusing of Gaussian laser beam in relativistic ponderomotive (RP) cold quantum plasma. When de Broglie wavelength of charged particles is greater than or equal to the inter particle distance or equivalently the temperature is less than or equal to the Fermi temperature, quantum nature of the plasma constituents cannot be ignored. In this context, we have reported self-focusing on account of nonlinear dielectric contribution of RP plasma by taking into consideration the impact of quantum effects. We have setup the nonlinear differential equation for the beam-width parameter by paraxial ray and Wentzel Kramers Brillouin approximation and solved it numerically by the Runge Kutta Fourth order method. Our results show that additional self-focusing is achieved in case of RP cold quantum plasma than relativistic cold quantum plasma and classical relativistic case. The pinching effect offered by quantum plasma and the combined effect of relativistic and ponderomotive nonlinearity greatly enhances laser propagation up to 20 Rayleigh lengths.

scholarly journals Weakly relativistic self-focusing of Gaussian laser beam in magnetized cold quantum plasma

2017 ◽  
Vol 35 (4) ◽  
pp. 699-705 ◽  
Author(s):  
M. Aggarwal ◽  
V. Goyal ◽  
Richa ◽  
H. Kumar ◽  
T.S. Gill
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Interparticle Distance ◽  
Beam Propagation ◽  
Magnetized Plasma ◽  
Quantum Plasma ◽  
Computational Technique ◽  
Gaussian Laser Beam ◽  
Self Focusing ◽  
Paraxial Ray

AbstractIn the present paper, we have studied self-focusing of Gaussian laser beam in weakly relativistic magnetized cold quantum plasma. When interparticle distance is comparable to the de Broglie wavelength of charged particles, we cannot neglect the quantum contribution of plasma constituents. Therefore, propagation characteristics are studied by taking in to account quantum contribution in the presence of static magnetic field applied along the beam propagation. Our results show that the magnetic field plays a key role in achieving additional focusing, it modifies the quiver motion of electrons by adding cyclotron frequency to the natural frequency of oscillating electrons during laser beam propagation. The results are compared with those of weakly relativistic quantum plasma and weakly relativistic magnetized plasma. The self-focusing is found to be more pronounced when axial magnetic field is increased in the present model. We have setup the non-linear differential equation for the evolution of beam-width parameter by well-known paraxial ray approximation and solved it with the help of computational technique.

scholarly journals Relativistic self-focusing and self-phase modulation of cosh-Gaussian laser beam in magnetoplasma

2011 ◽  
Vol 29 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Tarsem Singh Gill ◽  
Ravinder Kaur ◽  
Ranju Mahajan
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Field Distribution ◽  
Phase Modulation ◽  
Variational Approach ◽  
Beam Width ◽  
Propagation Characteristics ◽  
Gaussian Laser Beam ◽  
Self Phase Modulation ◽  
Self Focusing

AbstractIn this paper, we have investigated the propagation characteristics of cosh-Gaussian laser beam in magnetoplasma using relativistic nonlinearity. The field distribution in the medium is expressed in terms of beam width parameter an and decentred parameter b. An appropriate nonlinear Schräodinger equation has been solved analytically using variational approach. The behaviour of beam width parameter with dimensionless distance of propagation ξ for various b values is examined. Self-phase modulation and self-trapping is also studied under variety of parameters. Further, the effect of magnetic field on self-focusing of the beam have been explored.

scholarly journals Relativistic self-focusing of super-Gaussian laser beam in plasma with transverse magneticfield

2012 ◽  
Vol 30 (3) ◽  
pp. 509-516 ◽  
Author(s):  
Tarsem Singh Gill ◽  
Ranju Mahajan ◽  
Ravinder Kaur ◽  
Suhail Gupta
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Beam Width ◽  
Transverse Magnetic ◽  
Higher Order ◽  
Gaussian Laser Beam ◽  
Self Focusing ◽  
Higher Order Terms ◽  
Distinct Features ◽  
Power Curves

AbstractThis paper presents an investigation of a self-consistent, theoretical model, which explains the ring formation in a super-Gaussian laser beam propagating in plasma with transverse magnetic field, characterized by relativistic nonlinearity. Higher order terms (up to r4) in the expansion of the dielectric function and the eikonal have been taken into account. The condition for the formation of a dark and bright ring has been used to study focusing/defocusing of the beam. It is seen that inclusion of higher order terms does significantly affect the dependence of beam width parameter on the distance of propagation. Self-focusing of super-Gaussian beam is studied at various values of super-Gaussian coefficient, m and magnetic field. Further, we have studied some distinct features of critical power curves for varying values of magnetic field.

scholarly journals Dynamics of Gaussian spikes on Gaussian laser beam in relativistic plasma

2009 ◽  
Vol 27 (4) ◽  
pp. 587-593 ◽  
Author(s):  
A. Singh ◽  
M. Aggarwal ◽  
T.S. Gill
Keyword(s):  
Differential Equations ◽  
Laser Beam ◽  
Nonlinear Differential Equations ◽  
Beam Width ◽  
Main Beam ◽  
Gaussian Laser Beam ◽  
Runge Kutta Method ◽  
Self Focusing ◽  
Gaussian Perturbation ◽  
Paraxial Ray

AbstractIn the present paper, we have investigated the growth of a Gaussian perturbation superimposed on a Gaussian laser beam. The nonlinearity we have considered is of relativistic type. We have setup the nonlinear differential equations for beam width parameter of the main beam, growth and width of the laser spike by using the WKB and paraxial ray approximation. These are coupled ordinary differential equations and therefore these are simultaneously solved numerically using the Runge Kutta method. It has been observed from the analysis that self-focusing/defocusing of the main beam and the spike determine the growth dynamic of the spike.

scholarly journals Terahertz radiation by self-focused amplitude-modulated Gaussian laser beam in magnetized ripple density plasma

2015 ◽  
Vol 33 (4) ◽  
pp. 741-747 ◽  
Author(s):  
Ram Kishor Singh ◽  
R. P. Sharma
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Applied Magnetic Field ◽  
Magnetized Plasma ◽  
Thz Radiation ◽  
Gaussian Laser Beam ◽  
Spatial Profile ◽  
Self Focusing ◽  
Oscillatory Velocity ◽  
Density Plasma

AbstractThis paper presents a theoretical model for efficient terahertz (THz) radiation by self-focused amplitude-modulated laser beam in preformed ripple density plasma. The density of plasma is modified due to ponderomotive nonlinearity which arises because of the nonuniform spatial profile of the laser beam in magnetized plasma and leads to the self-focusing of the laser beam. The rate of self-focusing depends on the intensity of the amplitude-modulated beam as well as on the externally applied magnetic field strength. The electron also experiences time-dependent ponderomotive force by the laser beam at modulated frequency. A nonlinear current at THz frequency arises on account of the coupling between the ripple density plasma and nonlinear oscillatory velocity of the electrons. The yield of the generated THz radiation enhances with enhancement in self-focusing of the laser beam and applied magnetic field.

Self-focusing of Gaussian laser beam in relativistic cold quantum plasma

Optik ◽  
2013 ◽  
Vol 124 (2) ◽  
pp. 180-183 ◽  
Author(s):  
S.D. Patil ◽  
M.V. Takale ◽  
S.T. Navare ◽  
M.B. Dongare ◽  
V.J. Fulari
Keyword(s):  
Laser Beam ◽  
Quantum Plasma ◽  
Gaussian Laser Beam ◽  
Self Focusing
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