SINGLE-PASS AND DOUBLE-PASS PROPAGATION THROUGH COMPLEX PARAXIAL OPTICAL-SYSTEMS

A generalized form of spectral representation theory is developed and used with the ABCD formulation of the Huygens-Fresnel integral for studying optical wave propagation through a random medium in the presence of any complex paraxial optical system that can be characterized by an ABCD ray matrix. Formal expressions are developed for the basic optical field moments and various related second-order statistical quantities in terms of three fundamental moments of the first- and second-order complex phase perturbations. Special propagation environments include line-of-sight propagation, single-pass propagation through arbitrary ABCD optical systems, and double-pass propagation through the same random medium in the presence of an ABCD optical system. For illustrative purposes the method is used in the development of expressions for the mean and the normalized variance of the irradiance associated with the Fourier-transform-plane geometry of a lens and the enhanced backscatter effect (EBS) associated with irradiance and phase fluctuations of a reflected Gaussian-beam wave from a Gaussian mirror. The EBS analysis accounts for both finite size and finite focal length of the mirror.