scholarly journals Perturbative approach to the self-focusing of intense X-ray laser beam propagating in thermal quantum plasma

2018 ◽  
Vol 25 (11) ◽  
pp. 112104 ◽  
Author(s):  
R. Roozehdar Mogaddam ◽  
N. Sepehri Javan ◽  
K. Javidan ◽  
H. Mohammadzadeh
Keyword(s):  
Laser Beam ◽  
The Self ◽  
Quantum Plasma ◽  
Perturbative Approach ◽  
X Ray ◽  
Self Focusing

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.

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.

Deformation of a liquid surface by laser heating: laser-beam self-focusing and generation of capillary waves

1986 ◽  
Vol 64 (9) ◽  
pp. 1341-1344 ◽  
Author(s):  
J. Hartikainen ◽  
J. Jaarinen ◽  
M. Luukkala
Keyword(s):  
Laser Beam ◽  
Laser Heating ◽  
Surface Deformation ◽  
Liquid Surface ◽  
Capillary Waves ◽  
The Self ◽  
Self Focusing

The surface deformation of oil by laser heating is presented. The self-focusing of the reflected beam and the generation of capillary waves are observed.

Generation of Efficient Terahertz Radiation by Relativistic Self-Focusing of A Cosh-Gaussian Laser Beam in A Magnetized Plasma

2021 ◽  
Author(s):  
Gunjan Purohit ◽  
Bineet Gaur ◽  
Pradeep Kothiyal ◽  
Amita Raizada
Keyword(s):  
Laser Beam ◽  
Numerical Study ◽  
The Self ◽  
Magnetized Plasma ◽  
Thz Radiation ◽  
Gaussian Laser Beam ◽  
Plasma Parameters ◽  
Gaussian Profile ◽  
Self Focusing ◽  
Incident Laser Intensity

Abstract This paper presents a scheme for the generation of terahertz (THz) radiation by self-focusing of a cosh-Gaussian laser beam in the magnetized and rippled density plasma, when relativistic nonlinearity is operative. The strong coupling between self-focused laser beam and pre-existing density ripple produces nonlinear current that originates THz radiation. THz radiation is produced by the interaction of the cosh-Gaussian laser beam with electron plasma wave under the appropriate phase matching conditions. Expressions for the beamwidth parameter of cosh-Gaussian laser beam and the electric vector of the THz radiation have been obtained using higher-order paraxial theory and solved numerically. The self-focusing of the cosh-Gaussian laser beam and its effect on the generated THz amplitude have been studied for specific laser and plasma parameters. Numerical study has been performed on various values of the decentered parameter, incident laser intensity, magnetic field, and relative density. The results have also been compared with the paraxial region as well as the Gaussian profile of laser beam. Numerical results suggest that the self-focusing of the cosh-Gaussian laser beam and the amplitude of THz radiation increase in the extended paraxial region compared to the paraxial region. It is also observed that the focusing of the cosh-Gaussian laser beam in the magnetized plasma and the amplitude of the THz radiation increases at higher values of the decentered parameter.

Effect of a strong magnetic field on the self-focusing of a laser beam in InSb

1977 ◽  
Vol 40 (1) ◽  
pp. 315-320
Author(s):  
M. S. Sodha ◽  
V. K. Tripathi ◽  
D. P. Singh
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Strong Magnetic Field ◽  
The Self ◽  
Self Focusing

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.

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