The problem is discussed of determining the distribution of the intensity and of the degree of spectral coherence of a planar, secondary quasi-homogeneous source from the cross-spectral density function of the field measured over any plane that is parallel to the source. A solution to this problem is presented under the assumption that the degree of spectral coherence <i>g</i>(ρ<sub>1</sub> - ρ<sub>2</sub>, ω) of the quasi-homogeneous source does not vary appreciably across the source over distances |ρ<sub>1</sub> - ρ<sub>2</sub>| that are of the order of or less than the wavelength λ corresponding to the frequency ω. The results are illustrated by computational reconstruction of Gaussian-correlated quasi-homogeneous sources.
William H. Carter and Emil Wolf, "Inverse problem with quasi-homogeneous sources," J. Opt. Soc. Am. A 2, 1994-2000 (1985)