Abstract

Until now, spatial coherence properties of fields generated by partially coherent sources have mainly been studied in the far zone of the sources. This is largely because of the complexities of the calculations that are required when the points of observation are at finite distances from the source. Recently it has been noted that considerable simplification occurs when the field is statistically homogeneous, and this fact has been used to provide contours showing the spatial distribution of the degree of coherence throughout a field of this class. In our paper another statistically homogeneous field is considered, namely a field produced by a large, planar, secondary, Lambertian source. An expression is derived for the degree of spatial coherence of the field at all pairs of points in the half-space into which the source radiates. The results are illustrated by contour diagrams, which show the behavior of the modulus and of the phase of the degree of spatial coherence.

© 1990 Optical Society of America