The light filament as vector solitary wave

Abstract

We present an analytical approach to the theory of nonlinear propagation of femtosecond optical pulses with broad-band spectrum in gases. The vector character of the nonlinear third-order polarization is investigated in details, taking into account the carrier to envelope phase. The corresponding system of vector amplitude equations is written by using left-hand and right-hand circular components of the electrical field. We found that this system nonlinear equations admits $3D+1$ vector soliton solution with Lorentz shape. The solution presents relatively stable propagation and rotation with GHz frequency of the vector of the electrical field in plane, orthogonal to the direction of propagation. The evolution of the intensity profile demonstrate weak self-compression and week spherical wave in the first milliseconds of propagation.