  We present a novel proposal to generate an optical vortex beam by using the
coherent-superposition of multi-beams in a radial symmetrical configuration. In
terms of the generalized Huygens-Fresnel diffraction integral, we have derived
the general propagation expression for the coherent radial laser arrays. Based
on the derived formulae, we have analyzed the effects of the beamlet number,
the separation distance of the beamlets and the topological charge on the
intensity and phase distributions of the resulted beams. Our simulation results
show that optical vortices could be efficiently formed and generated due to the
interference and superposition effect of all the beamlets, during the
propagation process of the coherent radial laser arrays with the initial
well-organized phase distributions through the free space. In the focusing
system, the resulted beam near the focusing plane has the strong rotation
effect with the phase helicity.
