A Fourier optics approach to the dynamical theory of X-ray diffraction - perfect crystals

A new formalism is presented concerning the dynamics of X-rays in crystals. It is based on Takagiʹs equations and Fourier optics; it also offers an alternative to the usual Ewald-von Laue approach. The article does not give new results but shows a new way to formulate the dynamical theory of X-ray diffraction. In addition, it proposes a novel description of X-ray propagation based on the analogy between the dynamics of X-rays in crystals and that of two-level quantum systems.