Stimulated Raman Scattering of Ponderomotively Self Focused Cosh Gaussian Laser Beams in Axially Inhomogeneous Plasmas
Stimulated Raman scattering (S.R.S) of intense cosh-Gaussian (ChG) laser beams interacting with axially inhomogeneous plasmas has been investigated by incorporating the effect of self-focusing of the laser beam. An intense laser beam with frequency propagating through plasma gets coupled with a preexisting electron plasma wave (EPW) at frequency ω𝑒𝑝 and produces a back scattered wave at frequency. Semi analytical solution of the set of coupled wave equations for the pump, EPW and scattered wave has been obtained by using variational theory under W.K.B approximation. It has been observed that SRS reflectivity of plasma is significantly affected by the self-focusing effect of pump beam.
Keywords: Self-Focusing, Stimulated Raman Scattering, Cosh-Gaussian, Density Ramp.