Measuring vector field correlations using diffraction.

We present a method for efficiently measuring the 2 × 2 correlation matrix for paraxial partially coherent beams by using diffraction from small apertures and obstacles. Several representations for this matrix function of four spatial variables are discussed and illustrated with experimental results, including various alternative definitions of the spatial degree of coherence.

Experimental determining the coherent-mode structure of vector electromagnetic field through its decomposition in reference basis.

A technique for experimental determining the coherent-mode structure of electromagnetic field is proposed. This technique is based on the coherence measurements of the field in some reference basis and represents a nontrivial vector generalization of the dual-mode field correlation method recently reported by F. Ferreira and M. Belsley [Opt. Lett.38(21), 4350 (2013)]. The justifiability and efficiency of the proposed technique is illustrated by an example of determining the coherent-mode structure of some specially generated and experimentally characterized secondary electromagnetic source.