A STUDY OF THE PROPAGATION OF OPTICAL-SPECTRA USING A WAVELENGTH INDEPENDENT FORMULATION OF DIFFRACTION THEORY AND COHERENCE THEORY

Basic relations in diffraction theory and coherence theory are rederiv ed in spatial coordinates in units of a wavelength for each monochroma tic component of the field. It is found that each component behaves id entically in these coordinates independent of wavelength. This theory makes it clear that there is an intrinsic spectral shift that always o ccurs for any deterministic field as it propagates from a region near its sources into the far field. This theory also leads to a set of spe cial conditions under which a partially coherent field has the same sp ectrum over a plane near its sources and also at every point in its fa r field. These conditions are believed to be satisfied by the fields r adiated by natural thermal sources. Equations are given describing the relationships between the spectra of the source, the field near the s ource, and the radiation field under a wide range of conditions.