Generation of coherence vortex by modulating the correlation structure of random lights

A coherence vortex (CV) carrying topological-charge information in its correlation dimension is a new option for optical manipulation and communication. CV generation by directly modulating the correlation function enables a way to control the light field in this dimension. However, few experimental realizations on this issue have been reported because of the difficulty in phase modulation when the light arrays are of low coherence. In this paper, we propose a method for generating a CV by utilizing partially coherent light arrays. A proper design of random arrays at the input plane leads to a complex CV field at the output plane after free-space propagation. This generation mechanism works well for beamlets of low coherence. (C) 2019 Chinese Laser Press