Improvement of quantitative performance of imaging x-ray microscope by reduction of edge-enhancement effect

Abstract

A Fresnel zone plate (FZP) with a gradually-decreasing zone thickness from the centre to the outer region, called as an Apodization FZP (A-FZP) has been developed for the purpose of the improvements of imaging properties of imaging (full-field) x-ray microscope. Diffraction efficiency distribution of a A-FZP has a sloped-shouldered shape like a Gaussian, resulting a Gaussian-like pupil and Gaussian-like point spread function without any side peaks. Using this A-FZP, imaging properties at the peripheral region of the field of view was remarkably improved by decreasing edge-enhancement contrast and ringing which have been serious problem on the imaging properties with the conventional FZP objective optics.