Relativistic self-induced transmission of Gaussian laser beam through high density plasma

2021 ◽  
Author(s):  
Sonu Sen ◽  
Meenu Asthana Varshney
2015 ◽  
Vol 33 (4) ◽  
pp. 741-747 ◽  
Author(s):  
Ram Kishor Singh ◽  
R. P. Sharma

AbstractThis paper presents a theoretical model for efficient terahertz (THz) radiation by self-focused amplitude-modulated laser beam in preformed ripple density plasma. The density of plasma is modified due to ponderomotive nonlinearity which arises because of the nonuniform spatial profile of the laser beam in magnetized plasma and leads to the self-focusing of the laser beam. The rate of self-focusing depends on the intensity of the amplitude-modulated beam as well as on the externally applied magnetic field strength. The electron also experiences time-dependent ponderomotive force by the laser beam at modulated frequency. A nonlinear current at THz frequency arises on account of the coupling between the ripple density plasma and nonlinear oscillatory velocity of the electrons. The yield of the generated THz radiation enhances with enhancement in self-focusing of the laser beam and applied magnetic field.


2010 ◽  
Vol 82 (3) ◽  
pp. 035504 ◽  
Author(s):  
Deepak Tripathi ◽  
Lalita Bhasin ◽  
R Uma ◽  
V K Tripathi

2015 ◽  
Vol 33 (2) ◽  
pp. 257-263 ◽  
Author(s):  
Subodh Kumar ◽  
Ram Kishor Singh ◽  
Monika Singh ◽  
R. P. Sharma

AbstractThe effect of self-focusing and defocusing on terahertz (THz) generation by amplitude-modulated Gaussian laser beam in rippled density plasma is investigated. A stronger transient transverse current is generated by transverse component of ponderomotive force exerted by laser on electrons that drives radiation at the modulation frequency (which is chosen to be in the THz domain) because of the variation in intensity in the direction transverse to the laser propagation. Numerical simulations indicate the enhancement of THz yield by many folds due to self-focusing of laser beam in comparison with that without self-focusing. The transient focusing of laser beam and its effect on the generated THz amplitude has also been studied.


2018 ◽  
Vol 36 (2) ◽  
pp. 246-253 ◽  
Author(s):  
M. Kaur ◽  
P. C. Agarwal ◽  
S. Kaur ◽  
T. S. Gill

AbstractA nonparaxial investigation for propagation characteristics of q-Gaussian laser beam in rippled density plasma is studied by considering the relativistic nonlinearity. The field distribution in the medium is expressed in terms of q parameter and beam width parameter f. Nonlinear parabolic partial differential equation governing the evolution of complex envelope in slowly varying approximation is solved in a modulated density profile. Analytical theory of self-focusing including higher order terms in the expansion of dielectric function up to fourth order is developed and the variation of beam width parameter f with the distance of propagation for different parameters is studied. One may note that increased value of density ripple, laser intensity and depth of modulation, increases self-focusing whereas a lower value of q shows strong self-focusing. A comparative study between paraxial and nonparaxial study has also conducted. This study is useful for research in high energy density physics.


2021 ◽  
Author(s):  
Naveen Gupta ◽  
Sandeep Kumar ◽  
A Gnaneshwaran ◽  
Sanjeev Kumar ◽  
Suman Choudhry

2021 ◽  
Vol 53 (8) ◽  
Author(s):  
Quy Ho Quang ◽  
Thanh Thai Doan ◽  
Kien Bui Xuan ◽  
Thang Nguyen Manh

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