Spectral dependence of polarized radiation due to spatial correlations

We study the polarization of light emitted by spatially correlated sources. We show that, in general, polarization acquires a nontrivial spectral dependence due to spatial correlations. The spectral dependence is found to be absent only for a special class of sources where the correlation length scales as the wavelength of light. We further study cross correlations between two spatially distinct points that are generated due to propagation. It is found that such cross correlation leads to a sufficiently strong spectral dependence of polarization which can be measured experimentally.