In this paper we extend the calculation of the propagation of the mutual power spectrum, Γ⌃(x<sub>1</sub>,x<sub>2</sub>,ν), for nonlinear dielectrics to the case of optically lossy media. In particular, in the quasi-monochromatic limit, the dependence of the mutual coherence function of the second harmonic wave on the full fourth-order coherence of the incoming radiant flux is discussed. An experiment utilizing this phenomenon is suggested.
J. L. ZUCKERMAN and J. B. DEVELIS, "Propagation of Higher-Order Coherence Functions in Optically Lossy Media," J. Opt. Soc. Am. 57, 1176-1179 (1967)