Kubec Adam, Zdora Marie-Christine, Sanli Umut T, Diaz Ana, Vila-Comamala Joan, David Christian
Paul Scherrer Institut, Forschungsstrasse 111, 5232, Villigen PSI, Switzerland.
XRnanotech GmbH, Forschungsstrasse 111, 5232, Villigen PSI, Switzerland.
Nat Commun. 2022 Mar 14;13(1):1305. doi: 10.1038/s41467-022-28902-8.
Diffractive and refractive optical elements have become an integral part of most high-resolution X-ray microscopes. However, they suffer from inherent chromatic aberration. This has to date restricted their use to narrow-bandwidth radiation, essentially limiting such high-resolution X-ray microscopes to high-brightness synchrotron sources. Similar to visible light optics, one way to tackle chromatic aberration is by combining a focusing and a defocusing optic with different dispersive powers. Here, we present the first successful experimental realisation of an X-ray achromat, consisting of a focusing diffractive Fresnel zone plate (FZP) and a defocusing refractive lens (RL). Using scanning transmission X-ray microscopy (STXM) and ptychography, we demonstrate sub-micrometre achromatic focusing over a wide energy range without any focal adjustment. This type of X-ray achromat will overcome previous limitations set by the chromatic aberration of diffractive and refractive optics and paves the way for new applications in spectroscopy and microscopy at broadband X-ray tube sources.
衍射和折射光学元件已成为大多数高分辨率X射线显微镜不可或缺的一部分。然而，它们存在固有的色差。迄今为止，这限制了它们仅能用于窄带宽辐射，实际上将此类高分辨率X射线显微镜局限于高亮度同步辐射源。与可见光光学类似，解决色差的一种方法是将具有不同色散能力的聚焦和散焦光学元件组合起来。在此，我们展示了首个成功实现的X射线消色差透镜，它由一个聚焦衍射菲涅耳波带片（FZP）和一个散焦折射透镜（RL）组成。利用扫描透射X射线显微镜（STXM）和叠层成像技术，我们展示了在宽能量范围内无需任何焦距调整的亚微米级消色差聚焦。这种类型的X射线消色差透镜将克服此前由衍射和折射光学元件的色差所带来的限制，并为宽带X射线管源在光谱学和显微镜学中的新应用铺平道路。
