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 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 Self-focusing and self-phase modulation of an elliptic Gaussian laser beam in collisionless magnetoplasma

2006 ◽  
Vol 24 (3) ◽  
pp. 447-453 ◽  
Author(s):  
NARESHPAL SINGH SAINI ◽  
TARSEM SINGH GILL
Keyword(s):  
Laser Beam ◽  
Phase Modulation ◽  
Beam Width ◽  
Magnetized Plasma ◽  
Combined Effects ◽  
Gaussian Laser Beam ◽  
Self Phase Modulation ◽  
Self Focusing ◽  
Variation Approach ◽  
Self Trapping

The problem of nonlinear self-focusing of elliptic Gaussian laser beam in collisionless magnetized plasma is studied using variation approach. The dynamics of the combined effects of nonlinearity and spatial diffraction is presented. With a and b as the beam width parameters of the beam along x and y directions, respectively, the phenomenon of cross-focusing is observed where focusing of a results in defocusing of b and vice versa. Although no stationary self-trapping is observed, oscillatory self-trapping occurs far below the threshold. The regularized phase is always negative.

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 Self phase modulation of a Gaussian laser beam through a non linear thin film

1989 ◽  
Vol 24 (3) ◽  
pp. 411-415 ◽  
Author(s):  
F. Bloisi ◽  
L. Vicari ◽  
S. Martellucci ◽  
J. Quartieri ◽  
P. Cavaliere
Keyword(s):  
Thin Film ◽  
Laser Beam ◽  
Phase Modulation ◽  
Gaussian Laser Beam ◽  
Self Phase Modulation ◽  
Non Linear

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.

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.

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