• Naveen Gupta

Self-phase modulation (SPM) of q-Gaussian laser beams interacting nonlinearly with plasma channels has been investigated theoretically. Due to intensity gradient over the cross section of the laser beam the transverse component of Ponderomotive force becomes finite. This results in redistribution of carriers in the illuminated portion of the channel. The resulting index of refraction of the illuminated region of the channel resembles to that of graded index fibres that produces tight focusing of the laser beam. The reduction in transverse dimensions of the laser beam in turn leads to spread in transverse momentum of its photons. This transverse momentum spread then modifies the axial phase of the laser beam. Following Hamiltonian formulation, a set of coupled differential equations for the evolution of spot size and axial phase of the laser beam has been obtained. The equations so obtained have been solved numerically so see the effect of laser and channel parameters on the evolution of beam envelope.

q-Gaussian, Virial theory, Self-Focusing, Gouy Phase, Plasma Channel.

"Self-Phase Modulation of Tightly Focused q-Gaussian Laser Beam in Parabolic Plasma Channels", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 11, page no.235-238, November 2018, Available :http://www.jetir.org/papers/JETIRDR06037.pdf

"Self-Phase Modulation of Tightly Focused q-Gaussian Laser Beam in Parabolic Plasma Channels", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 11, page no. pp235-238, November 2018, Available at : http://www.jetir.org/papers/JETIRDR06037.pdf