Rocking Curves of X-ray Asymmetrical Laue Diffraction with Two-Dimensional Curvature of Wave Front

X-ray asymmetrical Laue diffraction in a perfect crystal with plane front surface was considered taking into account the two-dimensional curvature of a wave incident on the crystal. Using an appropriate Green function the dependences of rocking curves on deviation angles from selected exact Bragg direction were examined in the diffraction plane and in the direction perpendicular to the diffraction plane in locally plane wave approximation. The dependence of rocking curves on the degree of asymmetry of diffraction geometry was investigated. Analytical expressions for half widths of rocking curves in the diffraction plane and in the direction perpendicular to the diffraction plane are obtained. Some requirements to spatial and temporal coherence are estimated.