Fresnel波带片编码成像的高分辨重建

High-resolution reconstruction of Fresnel zone plate coded imaging

本文提出了一种新的Fresnel波带片编码成像的重建方法.与传统的重建方法相比,这种新方法可以实现更高的空间分辨水平.具体而言,传统意义上来讲,Fresnel波带片编码成像的空间分辨水平取决于编码波带片的最外环宽度.本文提出的置建方法突破了这一限制,可以达到最外环宽度的1/m(m为正整数),从而超越了通常意义上的瑞利极限.

Zone plate coded imaging is an experimental technique for particle and strong X-ray imaging, which is widely applied to astronomy, nuclear medicine, and laser inertial confinement fusion researches. From conventional perspective, spatial resolution of zone plate depends on the encoding zone plate width of outermost ring Ar with a size greater than 1.22△r. In X-ray region, however, the outermost ring width of Fresnel zone plate is limited by processing technology. Such a limitation makes it impossible to fabricate a sufficiently small zone plate, thus restricting the applications of Fresnel zone plate coded imaging. In this paper, we present a new reconstruction method of zone plate coded imaging by using a higher-order order Gabor zone plate. With the proposed method, higher spatial resolution can be achieved than with the regular methods, thus the spatial resolution is improved by 1/m times the width of outermost ring （where m is a positive integer）. Consequently such a breakthrough goes beyond the limits of Rayleigh criterion in general.