Nonparaxial gaussian beams: 3. Optical vortices

It is shown that an arbitrary nonparaxial laser vortex near a focal plane i n the free space should be represented as a discrete superposition of intri nsic vortices possessing elliptical cross sections. The intrinsic vortices, albeit degenerate with respect to the propagation constants, exhibit a cha racteristic spectrum of singularities and topological phases. (C) 2001 MAIK "Nauka/Interperiodica".