Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-25T04:25:02.128Z Has data issue: false hasContentIssue false
  • English
  • Français

Nonlinear relativistic self-focusing of laser radiation in plasmas: Arbitrary intensity

Published online by Cambridge University Press:  09 March 2009

M. Asthana ,
K.P. Maheshwari  and
M.S. Sodha
M. Asthana
Affiliation:
School of Physics, Devi Ahilya University, Indore-452001, India
K.P. Maheshwari
Affiliation:
School of Physics, Devi Ahilya University, Indore-452001, India
M.S. Sodha
Affiliation:
*Vice-Chancellor, Lucknow University, Lucknow, 226–007.
Get access Rights & Permissions [Opens in a new window]

Abstract

A paraxial theory of relativistic self-focusing of a Gaussian laser beam in plasmas, when the nonlinear part of the effective dielectric constant is arbitrarily large, is presented. The plasma is taken to be homogeneous without any density fluctuations being necessary. The approach of Akhmanov et al. based on the WKB and paraxial ray approximations has been followed. It is seen that the saturating nature of nonlinearity leads to two values of critical power of the beam (Pcrl and Pcr2) for self-focusing. When the power of the beam P lies between the two critical values (i.e., Pcr1 < P < Pcr2), the medium behaves as an oscillatory waveguide; the beam first converges and then diverges, converges again, and so on. For P > Pcr2 the beam first diverges, then converges, then diverges, and so on. Because the relativistic mechanism is instantaneous, the theory is applicable to the understanding of selffocusing of laser pulses also.

Type
Research Article
Information
Laser and Particle Beams , Volume 12 , Issue 4 , December 1994 , pp. 623 - 632
Copyright
Copyright © Cambridge University Press 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Akhmanov, S.A. et al. 1968 Sov. Phys. Usp. 10, 609.CrossRefGoogle Scholar
Borisov, A.B. et al. 1990 Phys. Rev. Lett. 65, 1753.CrossRefGoogle Scholar
Hauser, T. et al. 1988 J. Opt. Soc. Am. B 5, 10.CrossRefGoogle Scholar
Hauser, T. & Scheid, W. 1991 Laser and Particle Beams 9, 675.CrossRefGoogle Scholar
Hora, H. 1974 In Laser Interaction and Related Plasma Phenomena, Vol. 3B, Schwarz, H. and Hora, H., eds. (Plenum Press, New York), p. 803.Google Scholar
Hora, H. 1975 J. Opt. Soc. Amer. 65, 344.CrossRefGoogle Scholar
Hora, H. 1981 Physics of Laser Driven Plasmas (Wiley, New York).Google Scholar
Kaw, P.K. & Dawson, J. 1970 Phys. Fluids 13, 472.CrossRefGoogle Scholar
Siegrist, M.R. 1976 Opt. Commun. 16, 3.CrossRefGoogle Scholar
Sodha, M.S. et al. 1974 Self Focusing of Laser Beams in Dielectrics, Plasmas and Semiconductors (Tata McGraw-Hill Publ. Co. Ltd, New Delhi).Google Scholar
Solem, J.C. et al. 1989 IEEE J. Quant. Electr. 25, 2423.CrossRefGoogle Scholar
Spatschek, K.H., 1977 J. Plasma Phys. 18, 293.CrossRefGoogle Scholar
Sprangle, P. et al. 1987 IEEE Trans. Plasma Sci. 15, 145.CrossRefGoogle Scholar
Sprangle, P. et al. 1990a Phys. Rev. Lett. 64, 2011.CrossRefGoogle Scholar
Sprangle, P. et al. 1990b. Phys. Rev.A 41, 4463.CrossRefGoogle Scholar