Effect of light ellipticity on laser induced plasma

A mathematical model is formulated, that describes the laser beam propagation in non-linear media for the case of an arbitrary beam polarization and a spatially inhomogeneous refractive index. We consider the general wave equation derived directly from Maxwell equations and look for the solution in a form of the wave with a variable complex amplitude and cylindrical symmetry to study the plasma generation, defocusing and Kerr effects. The initial plasma distribution was created using the theory of multiphoton and tunneling ionization assuming an initial Gaussian and azimuthal Gauss-Bessel beam at the focus. The ionization yield of photoelectrons, the femtosecond filament behavior, plasma density and electron temperature depend on the polarization state of the incident photons.The analysis of the limiting solutions in the paraxial approximation for the case of azimuthal, linear and radial polarizations is performed. The dependence of the defocusing and Kerr effects on the light ellipticity is studied.