Use of the van Cittert-Zernike theorem for partially polarized sources

We introduce an extension of the van Cittert-Zernike theorem to spatially i ncoherent sources with partial polarization. We show through a simple examp le that fields generated by such sources can possess correlation matrices w ith interesting properties. In particular, we show that by suitable modulat ion of the polarization state across the incoherent source, the correlation between the orthogonal components of the field as well as the degree of po larization may drastically change on propagation. (C) 2000 Optical Society of America OCIS codes: 030.0030, 060.2380, 230.6080, 260.5430.