11 nm hard X-ray focus from a large-aperture multilayer Laue lens

Abstract

The focusing performance of a multilayer Laue lens (MLL) with 43.4 μm aperture, 4 nm finest zone width and 4.2 mm focal length at 12 keV was characterized with X-rays using ptychography method. The reconstructed probe shows a full-width-at-half-maximum (FWHM) peak size of 11.2 nm. The obtained X-ray wavefront shows excellent agreement with the dynamical calculations, exhibiting aberrations less than 0.3 wave period, which ensures the MLL capable of producing a diffraction-limited focus while offering a sufficient working distance. This achievement opens up opportunities of incorporating a variety of in-situ experiments into ultra high-resolution X-ray microscopy studies.

3D Nanofabrication of High‐Resolution Multilayer Fresnel Zone Plates

“…This negates one of the main advantages of fabricating FZPs via thin film deposition techniques, namely, the possibility to deposit extremely fine outermost zones for high resolution optics. Proposed solutions to this particular problem include stacking of binary FZPs to create tilted zones,18 multilayer Laue lens pairs,27, 28, 29, 30, 66 and depositing on drawn tapered fibers 67, 68. Stacking is interesting but is composed of several subsequent lithography steps, which increases the chances of fabrication errors and is ultimately limited by the number of lithography steps one can afford.…”

“…Realization of thicker zone plates with similar resolution would require nanofabrication of structures with extremely high aspect ratios. As a consequence, other types of optics such as Kirkpatrick–Baez mirrors (KBM),21, 22 compound refractive lenses (CRL)23, 24, 25, 26 and multilayer‐Laue lenses (MLL)27, 28, 29, 30, 31 are mostly used in this energy range. High resolution KBMs require a complicated active wavefront correction scheme 22.…”

Multilayer Fresnel zone plates for high energy radiation resolve 21 nm features at 12 keV

“…We are convinced that this resolution performance can be extrapolated to the HXR region, as the autocorrelation analysis of the HXR range diffraction experiment supports sub-30 nm fullpitch resolution of the optic. The results show that ML-FZPs are up-and-coming for focusing of hard X-rays to nano-sized focal spots required for direct imaging [1,23,57,58], spectroscopy and for nano-diffraction [33][34][35]59,60] by using ML-FZPs. When compared with the conventional FZP manufacturing technique, namely the EBL, ML-FZPs present a number of interesting characteristics.…”

“…Despite the success of FZPs in soft X-ray (SXR) microscopy which was facilitated by developments in the conventional fabrication technique of e-beam lithography (EBL), the development of FZPs for HXR remained challenging due to the need for very high aspect ratios which are usually out of limits of EBL (A r of up to about 25 is achievable with increasingly complex techniques) [14,15]. Recently, there have been improvements in focusing of HXR via various diffractive optics such as, multilayer Laue lenses, lithographic and multilayer FZPs achieving high resolutions and efficiencies [1,[16][17][18][19][20][21][22][23]. FZPs based on multilayer fabrication techniques (ML-FZPs) where a fiber core is coated with a multilayer and sliced to deliver the ML-FZP, overcome the problem of achieving a high aspect ratio by the nature of the fabrication method [19,[24][25][26][27][28][29][30][31][32].…”

Coherent X-ray diffractive imaging on the single-cell-level of microbial samples

“…More recent ptychographic studies investigate the maximum derivable information from ptychographic data under non-simple experimental conditions for the illuminating wave-eld or the object such as position uncertainties [20,110,182], partial coherence and multiple wavelenghts [15,44,78,299], multiple object planes [181,284] and undersampling of the recorded di racted intensities [71]. In the rst place, however, the probably most important result has been the understanding that the ptychographic method not only is able to solve for the encoded object information but also for the illuminating wave-eld [183,294,296] making ptychography a valuable tool for analysing the wave-elds of X-rays [134,144,159,160,265,268]. In principle, the decoupling of object and illuminating wave-eld makes the retrieved object information free of aberrations.…”