Self-focusing and waveguide propagation of radiation in the case of deep penetration of a metal by a laser beam

1985 ◽  
Vol 15 (11) ◽  
pp. 1515-1523 ◽  
Author(s):  
A G Borkin ◽  
S V Drobyazko ◽  
E B Levchenko ◽  
Yu M Senatorov ◽  
V V Turygin
Keyword(s):  
Laser Beam ◽  
Deep Penetration ◽  
Self Focusing ◽  
Waveguide Propagation

Self-focusing of cosh-Gaussian laser beam in collisional plasma: effect of nonlinear absorption

2021 ◽  
Author(s):  
Naveen Gupta ◽  
Sandeep Kumar ◽  
A Gnaneshwaran ◽  
Sanjeev Kumar ◽  
Suman Choudhry
Keyword(s):  
Laser Beam ◽  
Nonlinear Absorption ◽  
Collisional Plasma ◽  
Gaussian Laser Beam ◽  
Self Focusing ◽  
Plasma Effect

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.

Computer simulation of cylindrical laser beam self-focusing in a plasma

2004 ◽  
Vol 164 (1-3) ◽  
pp. 472-476
Author(s):  
D. Subbarao ◽  
Karuna Batra ◽  
Manik Bali ◽  
Sugata Mitra
Keyword(s):  
Computer Simulation ◽  
Laser Beam ◽  
Self Focusing

Dynamics of self-focusing and self-phase modulation of elliptic Gaussian laser beam in a Kerr-medium

Pramana ◽  
2000 ◽  
Vol 55 (3) ◽  
pp. 423-431 ◽  
Author(s):  
Tarsem Singh ◽  
Nareshpal Singh Saini ◽  
Shyam Sunder Kaul
Keyword(s):  
Laser Beam ◽  
Phase Modulation ◽  
Kerr Medium ◽  
Gaussian Laser Beam ◽  
Self Phase Modulation ◽  
Self Focusing

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.

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