APPLICATION OF THE PARABOLIC WAVE-EQUATION TO X-RAY-DIFFRACTION OPTICS

A new computational approach is suggested to the analysis of imaging p roperties of realistic X-ray Fresnel zone plates with high aspect rati o. Its mathematical basis is the parabolic wave equation (PWE) describ ing diffraction inside the zone plate body as well as wave propagation and focusing throughout the optical system. A finite-difference metho d is used for solving PWE in a truncated free-space domain with a perf ectly transparent artificial boundary. The results of global wave fiel d calculation are visualized by means of color graphics. Numerical est imates of resolution, diffraction efficiency and field of view enables one to compare imaging performance of realistic X-ray zone plates wit h an idealized plane Fresnel diffraction lens.