Table of Contents
Advances in Optics
Volume 2014 (2014), Article ID 942750, 5 pages
http://dx.doi.org/10.1155/2014/942750
Research Article

Self-Focusing of Hermite-Cosh-Gaussian Laser Beams in Plasma under Density Transition

Department of Physics, Lovely Professional University, Phagwara, Punjab 144411, India

Received 16 June 2014; Accepted 9 September 2014; Published 29 September 2014

Academic Editor: Kim Fook Lee

Copyright © 2014 Manzoor Ahmad Wani and Niti Kant. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Self-focusing of Hermite-Cosh-Gaussian (HChG) laser beam in plasma under density transition has been discussed here. The field distribution in the medium is expressed in terms of beam-width parameters and decentered parameter. The differential equations for the beam-width parameters are established by a parabolic wave equation approach under paraxial approximation. To overcome the defocusing, localized upward plasma density ramp is considered, so that the laser beam is focused on a small spot size. Plasma density ramp plays an important role in reducing the defocusing effect and maintaining the focal spot size up to several Rayleigh lengths. To discuss the nature of self-focusing, the behaviour of beam-width parameters with dimensionless distance of propagation for various values of decentered parameters is examined by numerical estimates. The results are presented graphically and the effect of plasma density ramp and decentered parameter on self-focusing of the beams has been discussed.