Power coupled between partially coherent vector fields in different states of coherence.

Abstract

A procedure is described for calculating the power coupled between collimated, partially coherent vector fields that are in different states of coherence. This topic is of considerable importance in designing submillimeter-wave optical systems for astronomy. It is shown that if the incoming field S has coherence matrix A, and the outgoing field D has coherence matrix B, then the power coupled is simply Ps = Tr(ATBT), where the elements of T project the basis functions of B onto those of A. A similar technique can be used to calculate the power coupled from the background of S to D. The scheme is illustrated by calculating the power coupled between two scalar, Gaussian Schell-model beams. The procedure can be incorporated into optical design software.