Vortex solitons in dispersive nonlinear Kerr type media
  We have investigated the nonlinear amplitude vector equation governing the evolution of optical pulses in optical and UV region. We are normalizing this equation for the cases of different and equal transverse and longitudinal size of optical pulses, of week and strong dispersion. This gives us the possibility to reduce the amplitude equation to different nonlinear evolution equations in the partial cases. For some of these nonlinear equations exact vortex solutions are found. Conditions for experimental observations of these vortices are determined. 
L. M. Kovachev, L. M. Ivanov, D. Y. Dakova, L. I. Pavlov, K. L.   Kovachev