M.V. Takale

Propagation of Hermite-cosh-Gaussian laser beams in non-degenerate germanium having space charge neutrality

In this paper, we analytically investigate Hermite-cosh-Gaussian (HChG) laser beam propagation in non-degenerate germanium having space charge neutrality for the first three mode indices. The field distribution in the medium is expressed in terms of beam-width parameter f and decentred parameter b. The differential equations for the f parameter are established by a parabolic wave equation approach under paraxial approximation. Analytical solutions are obtained under the condition R n < R d , where R n is the self-focusing length and R d is the diffraction length. The behaviour of the f parameter with the dimensionless distance of propagation η for various b values is examined by numerical estimates. The results are presented graphically.

Analytical investigation on domain of decentered parameter for self-focusing of Hermite-cosh-Gaussian laser beam in collisional plasma

In the present paper, an analytically investigated domain of decentered parameter and its effect on the self-focusing of Hermit-cosh-Gaussian (HChG) laser beams in a collisional plasma have been studied theoretically. The nonlinearity in the dielectric constant of plasma arising due to the nonuniform heating of carriers along the wavefront of the laser beam has been employed in the present investigation. The nonlinear differential equation of beam width parameter for various laser modes of HChG beam is obtained by following the standard Akhamanovs parabolic equation approach under Wentzel-Kramers-Brillouin and paraxial approximations. The analytical treatment has enabled us to define three distinct regions: self-focusing, self-trapping and defocusing, which are presented graphically.