Coherence retrieval via three-dimensional intensity measurement

Wigner distribution function (WDF) is a complete representation of the optical field with arbitrary coherent state and can be regarded as a local spectrum. It has unique advantages for representation, measurement and manipulation of partially coherent fields. Image sensors can only obtain the two-dimensional intensity data, which is the shearing projection of WDF. The shearing of WDF, which equals to the propagation of optical field, embodies the coherent properties of optical field. In this paper, a phase space retrieval method based on three-dimensional (3D) intensity focus stack combined with an iterative optimization is proposed. WDF with arbitrary coherent state can be reconstructed by 3D intensity sequences, which can realize the local spectrum retrieval and the analysis of spatial partially coherent fields.