Diffraction of paraxial partially coherent fields by planar obstacles in the Wigner representation

Abstract

The free-space propagation of paraxial, partially coherent stationary fields can be described in a simple and intuitive way through the use of the Wigner function. In this context, this function plays the role of a generalized radiance that is constant along straight lines or rays. The effect of diffraction by transverse planar opaque obstacles or apertures is considered here for this representation, and a simple analytic approximate formula is given for the case when the incident field is quasi-homogeneous, at least in the neighborhood of the obstacle's edges. In this result, diffraction is accounted for by including rays emanating from the obstacle's edges.