Model of a rectangular multi-Gaussian Schell-model vortex beam and its properties

Considering the theory of coherence, the rectangular multi-Gaussian Schell-model vortex beam (RMGSMV) beam generated by multi-Gaussian Schell-model source has been introduced, and the propagation properties of RMGSMV beam propagating in free space has been analyzed by using the derived equations. The effects of beam parameters on the properties of RMGSMV beam propagating in free space have been discussed. The results show that the RMGSMV beam propagating in free space can remain the dark hollow center at the short propagation distance, and the beam will gradually evolve into a beam with similar rectangular flat-topped profile as the propagation distance increases.