Propagation of non-uniform partially coherent beams in free space

This paper introduces the concept of non-uniform partially coherent beams and investigates the spatial coherence change during beam propagation. Results show that non-uniform spatial coherence would make significantly changes during propagation, which is completely different from the classical beams. These changes have relationships with propagation distance, spatial coherence, and intensity distribution of the source. The points adjoining self-coherence area would mutate when beams propagate from the source; the high coherence area in the source may decrease after the beams propagate a short distance. Curves of spatial coherence would not overlap after propagation, while the spatial coherence tends to be uniform with increasing propagation distance.