The structure of partially coherent fields

The general framework of optical coherence theory is now well established and has been described in numerous publications. This chapter provides an overview of recent advances, both theoretical and experimental, that have been made in a number of areas of classical optical coherence. These advances have been spurred on by the introduction of the space-frequency representation of partially coherent fields, and an increased emphasis on the spatial coherence properties of wave fields. The fundamental experiment to measure spatial coherence is Young's double-slit experiment. A number of important optical processes are influenced by the coherence properties of the wave field. Results relating to the propagation of partially coherent wavefields highlight some of the significant results relating to optical beams. The influence of coherence on focusing is summarized and reviewed, along with the scattering of partially coherent wave fields and its relation to inverse scattering problems is discussed. It has been shown that spatial correlation functions have interesting topological properties associated with their phase singularities; these properties and the relevant literature are discussed. The coherent mode representation and its applications are described and several techniques for the numerical simulation of wave fields with a prescribed statistical behavior are explained