Correlation theory of stationary electromagnetic fields

Abstract

In recent papers a class of second order correlation tensors was introduced and certain differential equations which govern their propagation were postulated. These correlation tensors, which may be regarded as natural generalizations of functions used in the analysis of partially coherent optical wavefields, characterize the correlations which exist between the electromagnetic field vectors at any two points in the field, at any two instants of time. In the present paper a derivation of the basic differential equations is presented; and it is shown that the two sets into which the equations naturally split are not independent, but in fact follow from each other as a consequence of certain symmetry properties which the correlation tensors exhibit.