相关论文: First Point-Spread Function and X-Ray Phase-Contra…
Emerging coherent X-ray scattering patterns of single-particles have shown dominant morphological signatures in agreement with predictions of the scattering model used for conventional protein crystallography. The key question is if and to…
A simple coherent-imaging method due to Paganin et al. is widely employed for phase-amplitude reconstruction of samples using a single paraxial x-ray propagation-based phase-contrast image. The method assumes that the sample-to-detector…
The demonstration of an optical fiber based probe for efficiently exciting the waveguide modes of high-index contrast planar photonic crystal (PC) slabs is presented. Utilizing the dispersion of the PC, fiber taper waveguides formed from…
X-ray cone-beam computed tomography (CT) has the notable features such as high efficiency and precision, and is widely used in the fields of medical imaging and industrial non-destructive testing, but the inherent imaging degradation…
We demonstrate a strategy for simulating wide-range X-ray scattering patterns, which spans the small- and wide scattering angles as well as the scattering angles typically used for Pair Distribution Function (PDF) analysis. Such simulated…
It is shown that the diffraction on a polycrystal can be used for investigation and diagnostics of X-ray radiation emitted in a forward direction by relativistic charged particles moving in crystalline or other targets or fields. Methods…
During the last five years, serial femtosecond crystallography using x-ray laser pulses has developed into a powerful technique for determining the atomic structures of protein molecules from micrometer and sub-micrometer sized crystals.…
The paper report new results of chromatic dispersion in Photonic Crystal Fibers (PCFs) through appropriate designing of index-guiding triangular-lattice structure devised, with a selective infiltration of only the first air-hole ring with…
In order to efficiently image a non-absorbing sample (a phase object), dedicated phase contrast optics are required. Typically, these optics are designed with the assumption that the sample is weakly scattering, implying a linear relation…
The effects of photon noise, aliasing, wavefront chromaticity and scintillation on the point spread function (PSF) contrast achievable with ground based adaptive optics (AO) are evaluated for different wavefront sensing schemes. I show that…
The point-spread function (PSF) of an adaptive optics (AO) system is often poorly known. This ignorance can lead to significant systematic errors in photometry. Since the degree of AO correction is sensitive to the observing conditions:…
A novel scheme for Zernike-type hard X-ray phase-contrast imaging is proposed. The scheme relies on X-ray dynamical diffraction in a two-block crystal system with parallel crystal plates of equal thickness. A phase shifter providing a…
We present the first astronomical observations obtained with an Apodizing Phase Plate (APP). The plate is designed to suppress the stellar diffraction pattern by 5 magnitudes from 2-9 lambda/D over a 180 degree region. Stellar images were…
We report on recent progress in the development of Laue lenses for applications in hard X/soft gamma-ray astronomy. Here we focus on the realization of a sector of such a lens made of 11 bent Germanium crystals and describe the…
We develop a speckle-tracking method for x-ray phase-contrast imaging, based on the concept of geometric flow. This flow is a conserved current associated with deformation of illuminating x-ray speckles induced by passage through a sample.…
Curved single crystals are widely employed in spectrometer designs in the hard X-ray regime. Due to their large solid angle coverage and focusing properties, toroidally bent crystals are extremely useful in applications where the output of…
In this article we have theoretically investigated the dispersion characteristics of dual-core PCF, based on square-lattice geometry by varying different parameters. The fiber exhibits a very large negative dispersion because of rapid slope…
The use of strongly bent crystals in spectrometers for pulses of a hard x-ray free-electron laser is explored theoretically. Diffraction is calculated in both dynamical and kinematical theories. It is shown that diffraction can be treated…
We propose an application of the Angular X-ray Cross-Correlation Analysis (AXCCA) to the scattered intensity distribution measured in three-dimensional (3D) reciprocal space from a single crystalline sample. Contrary to the conventional…
Scintillator-based X-ray imaging detectors are pivotal in numerous scientific and practical domains, including medical imaging, and security monitoring. Recent advancements have spurred interest in 4D X-ray imaging using synchrotron…