On two definitions of the three-dimensional degree of polarization in the near field of statistically homogeneous partially coherent sources

摘要

We investigate the role of the source coherence length in the two alternative definitions, [Phys. Rev. E 66, 016615 (2002)] and [Opt. Commun. 248, 333 (2005)], respectively, on the degree of polarization of a three-dimensional near field emitted by a random planar source. It is demonstrated that for the wide variety of statistically homogeneous sources, there are regimes where both definitions are identical. In particular, this occurs for fields from d-correlated, such as thermal sources. Further, we discuss how the excitation of surface waves influence whether those two definitions coincide. © 2012 Optical Society of America.