title: Analyzing the power coupled between partially coherent waveguide fields in different states of coherence.
abstract: A procedure is described for calculating the power coupled between partially coherent waveguide fields that are in different states of coherence. The method becomes important when it is necessary to calculate the power transferred from a distributed source S to a distributed load L through a length of multimode metallic, or dielectric, waveguide. It is shown that if the correlations between the transverse components of the electric and magnetic fields of S and L are described by coherence matrices M and M', respectively, then the normalized average power coupled between them is (eta) = Tr[MM']/Tr[M]Tr[M'], where Tr denotes the trace. When the modal impedances are equal, this expression for the coupled power reduces to an equation derived in a previous paper [J. Opt. Soc. Am. A 18, 3061 (2001)], by use of thermodynamic arguments, for the power coupled between partially coherent free-space beams.
authors.affiliation: Cavendish Laboratory, University of Cambridge, UK. stafford@mrao.cam.ac.uk
authors.forename: Stafford
authors.initials: S
authors.lastname: Withington
authors.forename: Ghassan
authors.initials: G
authors.lastname: Yassin