ABSTRACT
The study of Fourier optics allows to characterize the diffraction effects in a linear systems framework, which in turn facilitates an intuitive understanding of their effects. This chapter presents the basic formula for calculating diffraction effects in wave propagation problems: the Rayleigh-Sommerfeld diffraction formula. It discusses imaging for coherent and incoherent optical fields. The chapter also presents the introductory statistical optics concepts relevant to the imaging material. It provides discussions of optical coherence, imaging as an interferometric process, and an introduction to the photoelectric light detection process. The chapter also provides the basic formulation for calculating the optical field at an observation point due to a field in a diffracting aperture some distance away. It describes an interferometric view of imaging that ties the spatial coherence of an optical field to the statistical performance characteristics of an imaging system. The chapter shows that the coherence properties change with propagation and presents the basic theoretical result.
