  A high-accuracy solution of the diffraction problem has become necessary for
the treatment of certain special questions of statistical physics. This article
reports the creation of a computer program that serves as an instrumental
method of calculating the parameters of diffraction phenomena when complex
optical systems are being theoretically investigated. The program solves the
diffraction problem by a rigorous method based on Maxwell"s equations under
specified boundary conditions. An arbitrary for instance, diffuse configuration
of the initial light field is allowed. Reflective gratings with a linear or
crossed sinusoidal profile of the surface micro relief are considered as the
diffraction optical elements. The characteristics of the self-consistent total
light field can be calculated when several diffraction elements are present in
the system.
