Plasma‐wave production by two laser beams in an inhomogeneous plasma

1974 ◽  
Vol 45 (9) ◽  
pp. 3836-3839 ◽  
Author(s):  
G. Beaudry
Keyword(s):  
Plasma Wave ◽  
Inhomogeneous Plasma ◽  
Laser Beams

Generation of terahertz radiation via nonlinear mixing of laser beams in an inhomogeneous plasma

Optik ◽  
2015 ◽  
Vol 126 (24) ◽  
pp. 5430-5433
Author(s):  
Santosh Chauhan ◽  
J. Parashar ◽  
R. Kurchania
Keyword(s):  
Terahertz Radiation ◽  
Inhomogeneous Plasma ◽  
Laser Beams ◽  
Nonlinear Mixing

scholarly journals Electron plasma wave excitation by beating of two q-Gaussian laser beams in collisionless plasma

2016 ◽  
Vol 34 (2) ◽  
pp. 230-241 ◽  
Author(s):  
Arvinder Singh ◽  
Naveen Gupta
Keyword(s):  
Laser Beam ◽  
Plasma Wave ◽  
Electron Concentration ◽  
Collisionless Plasma ◽  
Electron Plasma ◽  
Spot Size ◽  
Laser Beams ◽  
Plasma Parameters ◽  
Electron Plasma Wave ◽  
Ponderomotive Nonlinearity

AbstractThis paper presents a scheme for excitation of an electron-plasma wave (EPW) by beating two q-Gaussian laser beams in an underdense plasma where ponderomotive nonlinearity is operative. Starting from nonlinear Schrödinger-type wave equation in Wentzel–Kramers–Brillouin (WKB) approximation, the coupled differential equations governing the evolution of spot size of laser beams with distance of propagation have been derived. The ponderomotive nonlinearity depends not only on the intensity of first laser beam, but also on that of second laser beam. Therefore, the dynamics of one laser beam affects that of other and hence, cross-focusing of the two laser beams takes place. Due to nonuniform intensity distribution along the wavefronts of the laser beams, the background electron concentration is modified. The amplitude of EPW, which depends on the background electron concentration, is thus nonlinearly coupled with the laser beams. The effects of ponderomotive nonlinearity and cross-focusing of the laser beams on excitation of EPW have been incorporated. Numerical simulations have been carried out to investigate the effect of laser and plasma parameters on cross-focusing of the two laser beams and further its effect on EPW excitation.

Simulation Study of Plasma Wave Generation and Nonlinearity in InSb Semiconductor

1998 ◽  
Vol 07 (02) ◽  
pp. 291-302
Author(s):  
K. Rajendran
Keyword(s):  
Plasma Wave ◽  
Large Amplitude ◽  
Current Drive ◽  
Particle Accelerator ◽  
Laser Beams ◽  
Strength Parameter ◽  
Laser Parameter ◽  
Transition To Chaos ◽  
Frequency Mismatch ◽  
Wave Breakdown

It is shown that the large amplitude plasma were driven by two collinear laser beams in InSb semiconductor exhibit bistability and hysteresis studied by computer simulation. The influence of collision, laser parameter and frequency mismatch were considered for the large amplitude plasma wave and transition to chaos and leading to plasma wave breakdown. It is confirmed by bifurcation diagram and poincare map. The laser pump strength parameter rather greater than critical value leading to the occurrence of bistability (instability) region. The results may be relevant to beat-wave current drive in Tokamak devices and to beat-wave particle accelerator in semiconductor plasma.

scholarly journals Generation of Second Harmonics of Relativistically Self-Focused q-Gaussian Laser Beams in Underdense Plasma with Axial Density Ramp

2021 ◽  
Author(s):  
Naveen Gupta ◽  
Sandeep Kumar
Keyword(s):  
Laser Beam ◽  
Plasma Wave ◽  
Pump Beam ◽  
Second Harmonic ◽  
Fluid Model ◽  
Intense Laser ◽  
Laser Beams ◽  
Variational Theory ◽  
Plasma Parameters ◽  
Pump Frequency

Abstract An investigation on frequency doubling of intense laser beams through the phenomenon of second harmonic generation (SHG) in underdense plasmas has been presented. In order to increase the efficiency of S.H.G the density profile of plasma has been considered in the shape of upward ramp. When laser beam with frequency !0 propagates through plasma, it makes the plasma electrons to oscillate at pump frequency. These oscillations of plasma electrons in the presence of thermal velocity generate a plasma wave at frequency !0. The generated plasma wave beats with the pump beam to double its frequency. Variational theory has been adopted to find semi analytical solution of the wave equation for the slowly varying envelope of the laser beam. By using hydrodynamic fluid model of plasma, nonlinear current density for SHG has been obtained. Emphasis are put on investigation of the effect of various laser and plasma parameters on propagation dynamics of pump beam and the power of generated second harmonics.

scholarly journals Beat wave excitation of electron plasma wave by coaxial cosh-Gaussian laser beams in collisional plasma

2015 ◽  
Vol 33 (4) ◽  
pp. 621-632 ◽  
Author(s):  
Arvinder Singh ◽  
Naveen Gupta
Keyword(s):  
Laser Beam ◽  
Plasma Wave ◽  
Electron Plasma ◽  
Spot Size ◽  
Collisional Plasma ◽  
Laser Beams ◽  
Theory Approach ◽  
Wave Excitation ◽  
Plasma Parameters ◽  
Electron Plasma Wave

AbstractThis paper presents a scheme for beat wave excitation of an electron plasma wave (EPW) by cross-focusing of two intense cosh-Gaussian (ChG) laser beams in an under dense collisional plasma. The plasma wave is generated on account of beating of two ChG laser beams of frequencies ω1 and ω2. Starting from Maxwell's equations, coupled differential equations governing the evolution of spot size of laser beams with distance of propagation have been derived by using Moment theory approach in Wentzel–Kramers–Brillouin approximation. The collisional nonlinearity depends not only on the intensity of first laser beam, but also on that of second laser beam. Therefore, dynamics of first laser beam affects that of other and hence cross-focusing of the two laser beams takes place. Numerical simulations have been carried out to investigate the effect of laser as well as plasma parameters on cross-focusing of laser beams and further its effect on power of excited EPW. It has been found that decentered parameters of the two laser beams have significant effect on power of EPW.

Resonant terahertz radiation from warm collisional inhomogeneous plasma irradiated by two Gaussian laser beams

2016 ◽  
Vol 23 (5) ◽  
pp. 053110 ◽  
Author(s):  
A. R. Niknam ◽  
M. R. Banjafar ◽  
F. Jahangiri ◽  
S. Barzegar ◽  
R. Massudi
Keyword(s):  
Terahertz Radiation ◽  
Inhomogeneous Plasma ◽  
Laser Beams

Effect of laser ripple on the beat wave excitation and particle acceleration

2007 ◽  
Vol 73 (1) ◽  
pp. 117-130 ◽  
Author(s):  
P. K. CHAUHAN ◽  
S. T. MAHMOUD ◽  
R. P. SHARMA ◽  
H. D. PANDEY
Keyword(s):  
Particle Acceleration ◽  
Laser Beam ◽  
Plasma Wave ◽  
Electron Plasma ◽  
Laser Beams ◽  
Wave Excitation ◽  
Mass Variation ◽  
Excitation Process ◽  
Electron Plasma Wave ◽  
Relativistic Mass

Abstract.This paper presents the effect of ripple on the plasma wave excitation process and acceleration of electrons in a laser produced plasma. The plasma wave is generated by the beating of two coaxial lasers of frequencies ω1 and ω2, such that ω1-ω2≅ωp. One of the main laser beams also has intensity spikes. The nonlinearity due to the relativistic mass variation depends not only on the intensity of one laser beam but also on the second laser beam. Therefore the behavior of the first laser beam affects the second laser beam, hence cross-focusing takes place. Owing to the interaction of ripple and the main laser beams, the ripple grows inside the plasma. The behavior of the ripple in the plasma affects the excitation of the electron plasma wave as well as the electron acceleration. The amplitude of the electron plasma wave and the electron energy are calculated, in the presence of ripple.

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