Weak scattering of multi-Gaussian Schell-model vortex beams on a deterministic medium

The scattering of a multi-Gaussian Schell-model (MGSM) vortex beam upon a deterministic medium is investigated within the accuracy of the first-order Born approximation. The explicit expression for the cross-spectral density function of the far-zone scattered field is derived, and some numerical examples are given to show the dependences of the spectral density and spectral degree of coherence on the source parameters and the scatterer parameter. It is found that by adjusting these parameters (especially the transverse coherence width of the source) we can shape the scattered beam profile into a quasi-Gaussian, flat-topped, or subsidence structure. Besides, for the distributions of the modulus of the spectral degree of coherence, secondary maxima occur when the incident beam is a vortex beam.