Partially coherent vortex beam with periodical coherence properties

We introduce a new kind of partially coherent vortex beam with periodical coherence properties, named optical coherence vortex lattices (OCVLs). With the help of the generalized Collins formula, we explore the propagation properties of the intensity and the complex degree of coherence of OCVLs focused by a thin lens. Compared to conventional partially coherent vortex beam, OCVLs display extraordinary propagation properties, i.e., a Gaussian beam spot evolves into multiple beam spots (i.e., intensity lattices) in the focal plane (i.e., in the far field). The intensity lattices with solid or hollow beamlets can be formed through manipulating the coherence width in the source plane. We also find that the topological charge of the OCVLs can be determined from the distribution of its complex degree of coherence in the focal plane. Furthermore, we report experimental generation of OCVLs. The OCVLs will be useful for particle trapping and information transfer.