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ABSTRACT: We report a novel type of x-ray interferometer employing a bilens system consisting of two parallel compound refractive lenses, each of which creates a diffraction limited beam under coherent illumination. By closely overlapping such coherent beams, an interference field with a fringe spacing ranging from tens of nanometers to tens of micrometers is produced. In an experiment performed with 12 keV x rays, submicron fringes were observed by scanning and moiré imaging of the test grid. The far field interference pattern was used to characterize the x-ray coherence. Our technique opens up new opportunities for studying natural and man-made nanoscale materials.
Physical Review Letters 08/2009; 103(6):064801. · 7.37 Impact Factor
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ABSTRACT: Optimizing the lens design and improving the technological process, we manufactured X-ray planar compound refractive lenses with vertical sidewalls up to 70 microns deep. The lens surface roughness in the order of 20 nm was attained. The minimal thickness of the material between two individual lenses of 2 õm was realized. Driven by the requirements of new 100 m-long beamlines at the ESRF, the first prototype chip of Si planar nanofocusing lenses was designed and manufactured. The technological breakthrough allows to reach the nanometer focusing. The optical tests of the new planar lenses were performed at the ESRF beamlines BM5 and ID15. The resolution below 200 nm was measured in the energy region of 15-80 keV. The best resolution of 150 nm was demonstrated at 50 keV energy. As a next step dedicated chip design for two-dimensional focusing with nanopositioning stages will be realized.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
09/2007;
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ABSTRACT: Stacking technique was developed in order to increase focusing efficiency of Fresnel zone plates at high energies. Two identical Si chips each of which containing Fresnel zone plates were used for stacking. Alignment of the chips was achieved by on-line observation of the moiré pattern from the two zone plates. The formation of moiré patterns was studied theoretically and experimentally at different experimental conditions. To provide the desired stability Si-chips with zone plates were bonded together with slow solidification speed epoxy glue. Technique of angular alignment in order to compensate a linear displacement in the process of gluing was proposed. Two sets of stacked FZPs were produced and experimentally tested to focus 15 and 50 keV X-rays. Gain in the efficiency by factor 2.5 was demonstrated at 15 keV. Focal spot of 1.8 μm vertically and 14 μm horizontally with 35% efficiency was measured at 50 keV. Forecast for the stacking of nanofocusing Fresnel zone plates was discussed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Physica Status Solidi (A) Applications and Materials 07/2007; 204(8):2817 - 2823. · 1.46 Impact Factor
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ABSTRACT: We presents the results of study of focusing and imaging properties of double-lens system for hard x-ray radiation consisting of two Fresnel zone plates (ZP) made from silicon. We demonstrate for the first time the phenomenon of focusing by two crystal ZP located at significant distance from each other. We investigate by both theoretically and experimentally the peculiarities of intensity distribution at the focal plane during a scan by second ZP normally to the optical axis of the system. We investigate as well the intensity distribution along the optical axis for our double-lens system from crystal ZP. We realize experimentally a registration of the focused image of the object by means of double-lens system based on ZP. Measurements are performed on the beam line BM-5 of the European Synchrotron Radiation Facility (ESRF) at the x-ray energy 9.4 keV. We elaborate a computer program for theoretical simulation of the optical properties of x-ray double-lens system based on ZPs. A calculation is made by convolution of transmission function and Kirchhoff propagator in paraxial approximation by means of Fast Fourier Transformation.
12/2005;
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ABSTRACT: Bragg‐Fresnel lens (BFL) as thin silicon dioxide strips grown on the surface of perfect silicon crystal was designed, manufactured and experimentally tested. In this case the BFL structure consists of a set of silicon dioxide rectangular shape etched zones arranged by the Fresnel zone law. The stress within coated and uncoated crystal regions is opposite in sign, whether tensile or compressive. The strain in the substrate crystal lattice directly underneath discontinuities in the deposited film give rise to phase difference between waves diffracted from coated and uncoated crystal regions. This phase difference is known to be dependent on the thickness and composition of film and substrate. The focusing properties of Si/SiO2 BFLs with 107 zones and 0.3 micrometer outermost zone width were experimentally studied as a function of the silicon oxide thickness in the range of 100 – 400 nanometers. It was shown that deformation Bragg‐Fresnel lenses could effectively focus hard X‐rays to a linear focal spot of about 2 microns. The efficiency of focusing was found to be about 16% at energy 10 keV. The developed lens design is a promising approach to extend the angular range of focusing by Bragg‐Fresnel optical elements and to avoid some drawbacks of BFL properties related to aspect‐ratio dependent etching. © 2004 American Institute of Physics
AIP Conference Proceedings. 05/2004; 705(1):744-747.
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ABSTRACT: We present integrated lens system (ILS), which consists of 6 compound refractive lenses with the same focal distance of 0.5m, but optimized for discrete set of energies such as 10, 12, 14, 16, 18, 20 keV. Focusing properties were tested at the ESRF BM‐5 and ID18F beamlines. It was shown, that all compound refractive lenses in the system focus X‐rays at 0.5 m with accuracy of 2% in changing energy according to the lens design. Focusing of 0.6 micron with the gain of 50 was demonstrated at 14 keV. © 2004 American Institute of Physics
AIP Conference Proceedings. 05/2004; 705(1):708-711.
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Design and Microfabrication of Novel X-Ray Optics II; 01/2004
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I Snigireva,
A Snigirev,
C Rau,
T Weitkamp,
V Aristov,
M Grigoriev, S Kuznetsov,
L Shabelnikov,
V Yunkin,
M Hoffmann,
E Voges
Nucl. Instrum. Meth. A. 01/2001; 467-468:982-985.
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X-Ray Micro- and Nano-Focusing: Applications and Techniques II; 01/2001
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V. Aristov,
M. Grigoriev, S. Kuznetsov,
L. Shabelnikov,
V. Yunkin,
T. Weitkamp,
C. Rau,
I. Snigireva,
A. Snigirev,
M. Hoffmann,
E. Voges
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ABSTRACT: Silicon refractive planar parabolic lenses with minimized absorption were fabricated by a combination of photolithography and dry-etching techniques. Focusing and spectral properties of the lenses were studied with synchrotron radiation in the energy range 8–25 keV at the European Synchrotron Radiation Facility. A focal spot of 1.8 μm with a gain of 18.5 and transmission of more then 80% was measured at 15.6 keV. The spectral characteristics were analyzed taking into account material dispersion and photon-energy attenuation in the hard x-ray range. © 2000 American Institute of Physics.
Applied Physics Letters 12/2000; 77(24):4058-4060. · 3.84 Impact Factor
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Opt. Commun. 01/2000; 177:33-38.
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ABSTRACT: Periodic domain inversion in a ferroelectric material (lithium niobate) has been studied using high-resolution x-ray diffraction topography. A domain-inverted structure of period 30 µm was fabricated in a LiNbO3 crystal with a thickness of 300 µm via electric-field poling. The synchrotron-radiation x-ray experiments were carried out at the ESRF micro- fluorescence, imaging and diffraction beamline (ID22). The experimental topograms and numerical simulations show that the image contrast can be explained in terms of a phase shift of the polarizability coefficient, h, in the domain-inverted region relative to the non-inverted part. This phase shift, 1.72, was found to be equivalent to the reflection, 00, from the domain-inverted part of the structure rather than to the reflection, 006, from the non-inverted part. The numerical simulation shows that the width of the transition region between inverted and non-inverted domains (domain walls) is 0.3 µm.
Journal of Physics D Applied Physics 12/1998; 32(10A):A160. · 2.54 Impact Factor
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ABSTRACT: A theoretical model of X-ray spectrum formation in the triple-crystal diffraction technique for the description of interference phenomena of X-ray scattering in crystals is presented. The proposed numerical algorithm of the solution of the corresponding inverse problems enables one to obtain a detailed two-dimensional strain distribution in the specimen crystal from the data of triple-crystal diffractometry.
Semiconductor Science and Technology 12/1998; 7(1A):A168. · 1.72 Impact Factor
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ABSTRACT: Recently it was found that transparent in hard X-ray (10–20 keV) range native and synthetic microobjects (10–20 microns size)
mounted in a X-ray beam give an image contrast in spite of very small refraction and negligible absorption. The information
obtained from registered diffraction patterns is deficient in the correct solution of the problem of phase-contrast computed
microtomography (determination of the shape, density variation, inhomogeneity, defects in microobjects). But it is possible
to obtain additional quantitative information using the so-called double-crystal diffraction technique where the X-ray wave
formed by the Bragg-Fresnel lens and transmitted through the transparent microobject is the incident wave for the crystal
analyzer.
Il Nuovo Cimento D 04/1997; 19(2):571-576.
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ABSTRACT: Coherent properties of the x‐ray beam delivered at the ESRF allow the observation of very weak perturbations of the wave front, resulting in the phase contrast. A straightforward experimental setup for phase contrast imaging is proposed and used to record holographic images from organic samples of 10–100 μm at energy 10–50 keV with the contrast up to 50%–100%. The theory of phase contrast imaging is considered and some theoretical estimations are made to reveal the performance of the proposed technique in terms of resolution, sensitivity, geometrical requirements, and energy range applicability. It is found that for carbon‐based fibers a detectable size with 2% contrast is 0.1 μm for 10 keV and -1 μm for 100 keV. It is demonstrated that the fine interference structure of the image is very sensitive to the shape, density variation, and internal structure of the sample. Some prospects for the practical use and future development of the new coherent techniques such as phase contrast microscopy, microtomography, holography, and interferometry at high energies are also discussed. © 1995 American Institute of Physics.
Review of Scientific Instruments 01/1996; · 1.37 Impact Factor
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ABSTRACT: Optimizing the lens design and improving the technological process, we manufactured X-ray planar compound refractive lenses with vertical sidewalls up to 70 microns deep. The lens surface roughness in the order of 20 nm was attained. The minimal thickness of the material between two individual lenses of 2 µm was realized. The optical tests of the new planar lenses were performed at the ESRF BM05 and ID15 beamlines. The technological breakthrough allows reaching the nanometer focusing. The resolution below 200 nm was measured in the energy region of 15-80 keV. The best resolution of 150 nm was demonstrated at 50 keV X-rays.
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V. Aristov,
M. Grigoriev, S. Kuznetsov,
L. Shabelnikov,
V. Yunkin,
C. Rau,
A. Snigirev,
I. Snigireva,
T. Weitkamp,
M. Hoffmann,
E. Voges
[show abstract]
[hide abstract]
ABSTRACT: Silicon planar parabolic refractive lenses including lenses with minimized absorption are created by the microfabrication technique. Focusing properties of the lenses were studied with synchrotron radiation in the X-ray energy range of 8–25 keV at the ESRF. The intensity transmission of a lens with minimized absorption is two times greater than that of simple parabolic lenses at 8 keV and in the X-ray energy range over 15 keV it exceeds 90%. Spectral and heatload properties of lenses with minimized absorption are discussed in detail.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
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ABSTRACT: The optical System composed of an X-ray silicon planar refractive lens and an X-ray planar waveguide with air gap has been characterized with synchrotron radiation. The guiding structure consisted of two silicon plates, clamped by permanent magnets and divided by a spacer made of thin magnetic film. The System was studied in the energy range 8-17 keV on the Optics beamline BMOS at the ESRF (Grenoble). It was shown, that the number of resonant modes in the beam exiting from the waveguide could be controlled by planar lens orientation, so that minimal number of modes could be obtained. Refractive optics elements and X-ray planar waveguides are a good combination for synchrotron sources of last génération and free electron lasers.
http://dx.doi.org/10.1051/jp4:200300067.
