scholarly journals Ray optics hamiltonian approach to relativistic self focusing of ultraintense lasers in underdense plasmas

2018 ◽  
Vol 167 ◽  
pp. 01003
Author(s):  
Alessandro Curcio ◽  
Maria Pia Anania ◽  
Fabrizio Giuseppe Bisesto ◽  
Massimo Ferrario ◽  
Francesco Filippi ◽  
...  
Keyword(s):  
Laser Intensity ◽  
Plasma Channel ◽  
Hamiltonian Formalism ◽  
Point Of View ◽  
The Self ◽  
Hamiltonian Approach ◽  
Self Focusing ◽  
Ultraintense Lasers ◽  
Underdense Plasmas ◽  
Underdense Plasma

The relativistic self focusing of an ultraintense laser propagating through an underdense plasma is analyzed from a geometrical optics point of view, exploiting the classical hamiltonian formalism. The distribution of the laser intensity along the self-generated plasma channel is studied and compared to measurements.

scholarly journals Effect of plasma channel non-uniformity on resonant third harmonic generation

2013 ◽  
Vol 31 (3) ◽  
pp. 531-537 ◽  
Author(s):  
Anuraj Panwar ◽  
Chang-Mo Ryu ◽  
Ashok Kumar
Keyword(s):  
Laser Pulse ◽  
Harmonic Generation ◽  
Plasma Channel ◽  
Second Harmonic ◽  
Third Harmonic Generation ◽  
Laser Frequency ◽  
The Self ◽  
Third Harmonic ◽  
The Third ◽  
Self Focusing

AbstractWe study the generation of resonant third harmonic laser radiation in a density non-uniform rippled plasma channel. An introduction of plasma channel non-uniformity strongly enhances the self-focusing and compression of main laser pulse at lower powers. In a deeper plasma channel, self-focusing is less sensitive to laser amplitude variation but increases compression. Plasma density ripple ‘nq’ leading to resonant third harmonic generation when kq = 4ω2p/3meω0cγ0, where ‘ω’p is electron plasma frequency, ‘ω0’ is laser frequency, and ‘γ0’ is the electron Lorentz factor. Third harmonic is produced through the beating of ponderomotive force induced second harmonic density oscillations and the oscillatory velocity of electrons at main laser frequency. The self-focusing and compression of the fundamental pulse periodically enhances the intensity of the third-harmonic pulse at lower powers of main laser. In a deeper plasma channel, the third harmonic power is less effective by self-focusing and the compression of main laser, and increase with main laser pulse power.

Combined influence of axial electron temperature and exponential plasma density ramp on the self-focusing of a chirped laser in plasma

2020 ◽  
Vol 75 (7) ◽  
pp. 671-675
Author(s):  
Niti Kant ◽  
Vishal Thakur
Keyword(s):  
Electron Temperature ◽  
Pulse Laser ◽  
Plasma Density ◽  
Beam Width ◽  
Spot Size ◽  
Higher Order ◽  
The Self ◽  
Chirped Pulse ◽  
Self Focusing ◽  
Paraxial Ray

AbstractAn analysis of the self-focusing of highly intense chirped pulse laser under exponential plasma density ramp with higher order value of axial electron temperature has been done. Beam width parameter is derived by using paraxial ray approximation and then solved numerically. It is seen that self-focusing of chirped pulse laser is intensely affected by the higher order values of axial electron temperature. Further, influence of exponential plasma density ramp is studied and it is concluded that self-focusing of laser enhances and occurs earlier. On the other hand defocusing of beam reduces to the great extent. It is noticed that the laser spot size reduces significantly under joint influence of the density ramp and the axial electron temperature. Present analysis may be useful for the analysis of quantum dots, the laser induced fusion and etc.

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.

scholarly journals Relativistic self-focusing in underdense plasma

2001 ◽  
Vol 152-153 ◽  
pp. 705-713 ◽  
Author(s):  
M.D Feit ◽  
A.M Komashko ◽  
A.M Rubenchik
Keyword(s):  
Self Focusing ◽  
Underdense Plasma
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