In order to investigate the principle and fabrication technique of Fresnel zone plates(FZPs),a diffractive optical element used in X-ray imaging with the best resolution currently is presented.A theoretical analysis of the spatial resolution depending on the outermost zone width is given.An analyrical expression of the diffraction efficiency in terms of thickness and X-ray refractive index of the zone plate is also provided.Electron beam lithography combined with X-ray lithography is employed to fabricate FZPs.Experimental results indicate that the outermost zone width is 150 nm and the aspect ratio is 4,which satisfies the X-ray imaging system requirements of high resolution.high aspect ratio as well as high precision.%研究了X射线成像波带片的工作原理和制作工艺.从理论上分析了波带片的空间分辨率与最外环宽度的关系,以及波带片衍射效率与厚度和折射率的关系.利用国家同步辐射实验室发展的加工工艺,即电子束光刻技术和X射线光刻技术结合制作波带片.实验结果表明:波带片最外环宽度为150 nm,高宽比为4,基本满足高分辨X射线成像波带片的高空间分辨率、大高宽比、高精度等要求.
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