Selected topics in quantum electronics, ieee journal of 18. Ptychographic coherent diffractive imaging pcdi is a significant advance in imaging allowing the measurement of the full electric field at a sample without use of any imaging optics. First, a new approach to xray crystallography, known as cdi, was first demonstrated in 1999 1 that allows structural determination of noncrystalline specimens and nanocrystals with a resolution limited only by the spatial. Coherent diffractive imaging cdi for biological applications at nslsii.
Starttoend simulation for single particle coherent. Dichroic coherent diffractive imaging pubmed central pmc. Fresnel coherent diffractive imaging from periodic samples. Coherent diffractive imaging and partial coherence garth j. The wide variety of coherent diffractive imaging cdi techniques bears witness to both the vitality and the infancy of the. Journal of applied crystallography 43, 15351539 2010. In situ coherent diffractive imaging yuan hung lo1,2, lingrong zhao1,3, marcus gallagherjones1, arjun rana1, jared j. Aug 16, 2011 dichroic coherent diffractive imaging. Here we introduce volume holograms as a new type of wavelength selective element for spectral imaging. By using iterative algorithms described earlier, the structure of the object is reconstructed from the diffraction pattern. A series of dichroic coherent diffraction patterns, ptychographically recorded, are numerically inverted using nonconvex and nonlinear optimization theory, and we follow the magnetic domain configuration evolution through part of its magnetization hysteresis loop by applying an external magnetic field. Cdi allows us to recover full information about the wavefield that passed sample ie.
This differs from conventional microscopy schemes which use objective lenses to produce an image of an object. Cdi is a novel form of lensless xray imaging ideally suited for nonperiodic objects or nanocystals resolution limited by radiation damage to sample need shorter, brighter pulses best experimentallyachieved resolutions with cdi. Osa phase tomography from xray coherent diffractive imaging. Coherent diffraction imaging cdi or coherent diffractive. Ctis uses a custom made diffractive optical element doe as the wavelength selective element and requires postcapture computation to recover the image cube. So far it has been confined solely to imaging of linear optical responses. Exit waves from different objects are reconstructed by phase retrieval algorithms, and are shown to be dominated by waveguiding within the sample. Among the techniques which are currently being developed, coherent diffractive imaging cdi is emerging as one of the most promising, offering the potential of very high resolution lensless imaging of noncrystallographic samples. Ptychography is a form of scanning diffractive imaging that can successfully retrieve the modulus and phase of both the sample transmission function and the illuminating probe.
Osa coherent diffractive imaging beyond the projection. We study extremeultraviolet wave propagation within optically thick nanostructures by means of highresolution coherent diffractive imaging using highharmonic radiation. A hybrid imaging system consisting of both refractive and diffractive lenses is analyzed, especially, with the undesired diffraction orders of the diffractive lens taken into account. Hawk is a package for the analysis and phasing of diffraction patterns from single particle diffraction experiments. Lensless xray microscopy requires the recovery of the phase of the radiation scattered from a specimen. The technique is robust, fastconverging, and yields the. In cdi, a highly coherent beam of xrays, electrons or other wavelike particle or photon is incident on an object the beam scattered by the object produces a. Studies of electrode structures and dynamics using coherent x. Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit. Dichroic resonant soft xray scattering can be successfully combined with coherent diffraction approaches such as iterative phase retrieval 1719, fourier transform.
Aug 16, 2011 an alternative approach to nanoscale dichroic microscopy is resonant xray coherent diffractive imaging cdi, whereby the diffraction pattern formed by scattering a coherent xray beam from a sample is inverted numerically to form an image of the sample. Here we present a novel approach to lensless imaging of an extended magnetic nanostructure, in which a scanned series of dichroic coherent diffraction patterns is recorded and numerically inverted to map its magnetic domain configuration. Coherent xray diffraction imaging cxdi is a powerful, elegant, and rapidly. An alternative approach to nanoscale dichroic microscopy is resonant xray coherent diffractive imaging cdi, whereby the diffraction pattern. It is defined as the bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacleaperture. This paper examines both current and future requirements for detectors in coherent xray diffractive imaging. Dynamic diffraction artefacts in bragg coherent diffractive. Coherent diffractive imaging cdi recent years have witnessed two revolutionary developments in xray science. A set of criteria for a suitable detector for a specific form of cxdi, fresnel coherent diffractive imaging, is derived. May 29, 2015 in 1999, ucla professor john miao pioneered a technique called coherent diffractive imaging, or cdi, which allows scientists to recreate the 3d structure of noncrystalline samples or nanocrystals. Article pdf available in proceedings of the national academy of sciences 10833. Starttoend simulation for single particle coherent diffractive imaging.
Two 1,064nm laser line mirrors were utilized as dichroic mirrors to. An intense 25 fs, 4 10 wcm2 pulse, containing 1012 photons at 32 nm wavelength, produced a coherent diffraction pattern from a nanostructured nonperiodic object, before destroying it at 60,000 k. At nlcta, we exploit such techniques for the diagnosis of the density distribution of the intense electron beams typically utilized in an xray fel itself. Coherent diffractive imaging cdi is a lensless technique for 2d or 3d reconstruction of the. The newly emerging technology of xray freeelectron lasers xfels has the potential to revolutionise molecular imaging. John maio ucla, thomas earnest lbnl, david shapiro bnl, enju lima bnl, wayne hendrickson columbia universitybnl. In addition, it enables the imaging of samples with arbitrarily large spatial dimensions, at a spatial resolution limited solely by the coherent xray flux, wavelength, and stability of the sample. Coherent diffractive imaging of biological samples at. In cdi, the spatial resolution is not limited by the quality of the optical elements but. We present a method for observing complex amplitude fields by using a singlepixel camera without reference light and imaging optics. Coherent x rays provided by the xray freeelectron laser fel have kindled strong interest in sophisticated diffraction imaging techniques. Observations about the challenges to soft xray detector science from this new imaging technique are discussed. Dichroic coherent diffractive imaging article pdf available in proceedings of the national academy of sciences 10833. Maximumlikelihood refinement for coherent diffractive imaging.
Effectively, the objective lens in a typical microscope is replaced with software to convert from the reciprocal space diffraction pattern into a real. Pdf bragg coherent diffractive imaging of strain at the nanoscale. The main topics that will be tackled are phasesensitive xray imaging, synchrotron xray tomography, coherent xray imaging methods with xray optics andor lensless and ultrafast time resolved imaging using fels. Coherent diffractive imaging with xray lasers max felix hantke issn 16516214 isbn 9789155497484 urn.
Nonlinear ptychographic coherent diffractive imaging. In cdi, the spatial resolution is not limited by the quality of the optical elements but by the highest spatial frequencies measured in the xray diffraction pattern. Gulden deutsches elektronensynchrotron desy, notkestra. Coherence measurements and coherent diffractive imaging at flash i. Coherent resonant soft xray scattering study of magnetic textures. Coherence and sampling requirements for diffractive imaging. Dichroic coherent diffractive imaging escholarship. Bragg coherent diffractive imaging bcdi emerged recently as a powerful tool to probe the internal deformation. Soft xray spectromicroscopy using ptychography with randomly. Phase tomography from xray coherent diffractive imaging projections. Coherent diffractive imaging with lower coherence laboratory. In situ coherent diffractive imaging nature communications. An alternative approach to nanoscale dichroic microscopy is resonant xray coherent diffractive imaging cdi, whereby the diffraction pattern formed by scattering a coherent xray beam from a sample is inverted numerically to form an image of the sample. The workshop will be focused on recent advances and future prospects in imaging technologies and their applications.
Understanding electronic structure at the nanoscale is crucial to untangling fundamental physics puzzles such as phase separation and emergent behavior in. All cdi techniques ultimately rely on the collection of intensity distributions after a macroscopic propagation distance. Coherent diffractive imaging cdi is a lensless technique for 2d or 3d reconstruction of the image of nanoscale structures such as nanotubes, nanocrystals, porous nanocrystalline layers, defects, potentially proteins, and more. Manuel guizarsicairos, ana diaz, mirko holler, miriam s.
Aug 11, 2011 polycdi extends the capabilities of coherent diffractive imaging cdi, a lensless imaging technique that has been a mainstay for experiments observing matter on the scale of xray wavelengths. New coherent diffractive imaging techniques, such fresnel coherent diffractive imaging fcdi, allows quantitative phase information with exceptional dose efficiency, high contrast, and nanoscale. Detectors for xray coherent diffractive imaging sciencedirect. Ptychographic coherent di ractive imaging pcdi is a signi. Reconstruction of an object from the modulus of its fourier transform. Xfel singleparticle diffractive imaging pipeline involves recording singleshot diffraction patterns of the targetobject before the destruction due to ionization and coloumb explosion top, computational purification for expected singleparticle diffraction patterns, orientation determination, classification into 2d class averages, and the 3d merging of intensities in the.
Fresnel coherent diffractive imaging fcdi is a relatively recent addition to the suite of imaging tools available at third generation xray sources. Coherent diffraction imaging cdi overcomes the resolution limit of xray. Bragg coherent diffractive imaging of strain at the nanoscale. Dissertation presented at uppsala university to be publicly examined in e10. Coherent xray diffractive imaging cxdi is a relatively novel imaging method that can produce an image of a sample without using optics between the sample and detector see fig. Researchers rapidly finding new applications for coherent. Conventional experiments using cdi assume a perfectly coherent beam and utilize plane wave illumination of the sample. Coherent diffractive imaging cdi has been widely applied in the physical and biological. Miao et al coherent xray diffraction imaging 3 pixilated array detector. The images are not produced by a lens, but by means of a powerful computer program. Coherent xray imaging brookhaven national laboratory. The experiments provide a direct visualization of extremeultraviolet guided. Tripathi a1, mohanty j, dietze sh, shpyrko og, shipton e, fullerton ee, kim ss, mcnulty i. Coherent diffractive imaging methods in a traditional microscope, a lens is used to collect the light scattered by a sample and thereby recover an image.
Coherence measurements and coherent diffractive imaging at flash. It has attracted a great deal of attention and interest owing to its unique. Coherent diffractive imaging cdi also called lensless imaging is an alternative to the classical brightfield, darkfield and phase contrast microscopy. Digital comprehensive summaries of uppsala dissertations from the faculty of science and technology 1451.
Introduction using the software plans and summary the 4th international workshop on fel science dixe. In the method, an object is illuminated with coherent light, and the propagating field is captured in multiple intensity measurements using a single photodetector and a spatial light modulator upon which different patterns are sequentially displayed. May 1718, 2010 brookhaven national laboratory, bldg. Lensless imaging with coherent hard and soft xrays is a rapidly. Use of a complex constraint in coherent diffractive imaging. It shares the strengths of other coherent diffractive techniques. Unlike holographic methods, it does not require a reference wave or precision optics. Here we report the first experimental demonstration of this principle using the flash soft xray freeelectron laser. Dmr 1548924 and the darpa pulse program through a grant from amrdec. Over the past few years, cdi has evolved into different methods which we classify here for convenience of discussion into four broad categories. Coherent diffraction imaging lensless imaging eric welch, sara mohamed, ling zeng, weilun qin august 7, 2015.