Abstract:A new total-reflection zone plate that consists of a reflective zone pattern with varied-space on a flat substrate was fabricated for hard X-ray nanofocusing. This device is much easier to fabricate than other focusing devices. This is because its focusing size is much smaller than its finest constituent structure since it exploits the effect of glancing X-rays by having a small total reflection angle. Its focusing properties were evaluated using 10-keV X-rays and a focusing size of 14.4 nm was achieved.
“…In addition, ellipsoidal focusing mirrors with a multilayer coating can potentially realize a focus size of nearly 1 nm with a long working distance and a high flux owing to the wide energy bandwidth and large spatial aperture 51 , 52 (see Fig. 7 ), in contrast to other optics that realized approximately 10-nm focusing property 53 – 57 . Figure 7 Layout of focusing optics using ellipsoidal mirrors.…”
Cutting-edge hard X-ray microscopy strongly depends on sophisticated focusing optics and ultrabright X-ray sources at synchrotron-radiation and X-ray free-electron laser (XFEL) facilities. These facilities typically provide two-dimensional nanofocusing X-ray beams by combining one-dimensional focusing mirrors. However, single-reflecting two-dimensional focusing mirrors with an ellipsoidal surface, which are well-known to possess high efficiency, have limited microfocusing applications. In this paper, we present an ultrahigh-precision ellipsoidal mirror for two-dimensional X-ray nanofocusing by overcoming the difficulties faced in the manufacturing process of its aspherical surface, including the surface-processing methods and surface metrology. The developed mirror has nanoscale accuracy, and it achieves focus size of 85 nm × 125 nm (full width at half maximum) using 7-keV X-rays. Two-dimensional focus was demonstrated in the same focal plane by resolving 50-nm test structures by scanning X-ray microscopy using a focusing beam. These achievements represent an important first step toward realizing two-dimensional aspherical mirrors with complex designs, in addition to ultralow loss and unprecedented small focusing property for extensive optical applications in synchrotron-radiation and XFEL facilities as well as in other scientific fields that require ultraprecision optical surfaces.
“…In addition, ellipsoidal focusing mirrors with a multilayer coating can potentially realize a focus size of nearly 1 nm with a long working distance and a high flux owing to the wide energy bandwidth and large spatial aperture 51 , 52 (see Fig. 7 ), in contrast to other optics that realized approximately 10-nm focusing property 53 – 57 . Figure 7 Layout of focusing optics using ellipsoidal mirrors.…”
Cutting-edge hard X-ray microscopy strongly depends on sophisticated focusing optics and ultrabright X-ray sources at synchrotron-radiation and X-ray free-electron laser (XFEL) facilities. These facilities typically provide two-dimensional nanofocusing X-ray beams by combining one-dimensional focusing mirrors. However, single-reflecting two-dimensional focusing mirrors with an ellipsoidal surface, which are well-known to possess high efficiency, have limited microfocusing applications. In this paper, we present an ultrahigh-precision ellipsoidal mirror for two-dimensional X-ray nanofocusing by overcoming the difficulties faced in the manufacturing process of its aspherical surface, including the surface-processing methods and surface metrology. The developed mirror has nanoscale accuracy, and it achieves focus size of 85 nm × 125 nm (full width at half maximum) using 7-keV X-rays. Two-dimensional focus was demonstrated in the same focal plane by resolving 50-nm test structures by scanning X-ray microscopy using a focusing beam. These achievements represent an important first step toward realizing two-dimensional aspherical mirrors with complex designs, in addition to ultralow loss and unprecedented small focusing property for extensive optical applications in synchrotron-radiation and XFEL facilities as well as in other scientific fields that require ultraprecision optical surfaces.
“…Fresnel zone plates (FZPs) are one of the most popular X-ray optical devices, for the following reasons: they have superior optical characteristics such as high spatial resolution up to several tens of nanometers (Chao et al, 2012;Chen et al, 2011;Suzuki et al, 2010a;Takeuchi et al, 2015;Takano et al, 2010;Dö ring et al, 2013), they are easy to align, and they are commercially obtainable ideal devices. Using several kinds of FZPs we have developed several kinds of hard X-ray microscope/tomography systems at the large synchrotron radiation facility SPring-8 (Takeuchi et al, 2012(Takeuchi et al, , 2013, such as a scanning X-ray microscope (Takeuchi et al, 2010), an imaging (full-field) X-ray microscope (Takeuchi et al, 2002(Takeuchi et al, , 2006Uesugi et al, 2006), and a combination of these two optics called a scanning-imaging X-ray microscope (SIXM).…”
Fresnel zone plates with apodized apertures [apodization FZPs (A-FZPs)] have been developed to realise Gaussian beam optics in the hard X-ray region. The designed zone depth of A-FZPs gradually decreases from the center to peripheral regions. Such a zone structure forms a Gaussian-like smooth-shouldered aperture function which optically behaves as an apodization filter and produces a Gaussian-like focusing spot profile. Optical properties of two types of A-FZP, i.e. a circular type and a one-dimensional type, have been evaluated by using a microbeam knife-edge scan test, and have been carefully compared with those of normal FZP optics. Advantages of using A-FZPs are introduced.
“…Recent progress in optics to produce nano-focused x-rays has been dramatic [1][2][3], enabling x-ray nano-probe analysis. For the ultimate nano-beam application, practical use of a ~100-nm beam can meet the strict requirements for solving current problems in industrial and scientific research, for example, local elemental analysis in fuel cells, nano-x-ray absorption fine structure (XAFS) of a single particle of a catalyst and x-ray magnetic circular dichroism (XMCD) magnetometry in a single magnetic dot for high-density memory.…”
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