Polarization structure of nonparaxial spatial solitons- "optical needles" in media with different mechanisms of self-focusing nonlinearity

This report investigates, both semianalytically and numerically, nonparaxial transversely two-dimensional spatial solitons for an arbitrary mechanism of the medium Kerr nonlinearity when the phenomenon of rotation of the polarization ellipse takes place. Numerically, the nonlinear propagation of laser radiation in the form of a fairly long pulse and a narrow beam has been studied. The effective self-focusing and formation of optical needles occur in the centre of the pulse. The field longitudinal component is especially large in the case of orientation mechanism of self-focusing.