Near field diffraction analysis and simulate about nanascale of Fresnel zone plate

摘要

In this paper, we calculated the numeric results of diffraction field in space of X-ray (λ=4.5nm) Fresnel zone plate based on angular spectrum method, analyzed the axial and radial distribution patterns of X-ray Fresnel zone plate. The Full Width at Half-Maximum (FWHM), Depth Of Focus (DOF) and Strehl efficiency of focus spot were studied. Discussed the relationships between FPZ's design parameter and focus spot properties. At the condition of λ=4.5nm and the outmost width Wn=50nm, the size of focus spot is proportional to the outmost width, and increase slowly with the increase of number of zones and focus length; the DOF of focus spot increase at first; when the focus length increased to 40μm, the DOF incline to a constant; the focus spot's Strehl efficiency increased slowly with the increase of number of zones and focus length.