Caustics of Vortex Optical Beams

The caustics of vortex optical beams have been investigated. An asymptotic method of calculating vortex-beam caustic surfaces is developed. The statement of the inverse problem of the formation of axial caustics of the desired form is considered. It is shown that the presence of the vortex component leads to the formation of an axisymmetric caustic surface, the characteristic diameter of which increases with an increase in the topological charge.