Anne Sakdinawat

Massively parallel X-ray holography

Stefano Marchesini, 2 Sébastien Boutet, 4 Anne E. Sakdinawat, Michael J. Bogan, Sas̆a Bajt, Anton Barty, Henry N. Chapman, 6 Matthias Frank, Stefan P. Hau-Riege, Abraham Szöke, Congwu Cui, Malcolm R. Howells, David A. Shapiro, John C. H. Spence, Joshua W. Shaevitz, Johanna Y. Lee, Janos Hajdu, 4 and Marvin M. Seibert Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550, USA. Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron rd. Berkeley, CA 94720, USA∗ Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, California 94025, USA. Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, Box 596, SE-75124 Uppsala, Sweden. Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. 6 Centre for Free-Electron Laser Science U. Hamburg, DESY, Notkestraße 85, Hamburg, Germany. Department of Physics and Astronomy, Arizona State University, Tempe, AZ 85287-1504, USA Department of Physics and Lewis-Sigler Institute, 150 Carl Icahn Laboratory, Princeton, New Jersey 08544, USA. Department of Plant and Microbial Biology, University of California, Berkeley, 648 Stanley Hall 3220, Berkeley, California 94720, USA. (Dated: February 9, 2008)

High numerical aperture tabletop soft x-ray diffraction microscopy with 70-nm resolution.

Light microscopy has greatly advanced our understanding of nature. The achievable resolution, however, is limited by optical wavelengths to ≈200 nm. By using imaging and labeling technologies, resolutions beyond the diffraction limit can be achieved for specialized specimens with techniques such as near-field scanning optical microscopy, stimulated emission depletion microscopy, and photoactivated localization microscopy. Here, we report a versatile soft x-ray diffraction microscope with 70- to 90-nm resolution by using two different tabletop coherent soft x-ray sources—a soft x-ray laser and a high-harmonic source. We also use field curvature correction that allows high numerical aperture imaging and near-diffraction-limited resolution of 1.5λ. A tabletop soft x-ray diffraction microscope should find broad applications in biology, nanoscience, and materials science because of its simple optical design, high resolution, large depth of field, 3D imaging capability, scalability to shorter wavelengths, and ultrafast temporal resolution.

Soft-x-ray microscopy using spiral zone plates

Phase sensitive soft-x-ray microscopy methods enable the study of specimens for which phase effects are a prevalent contrast mechanism. One way to detect these phase effects is to optically implement the radial Hilbert transform by using spiral zone plates (SZPs), which results in the isotropic measurement of the amplitude and phase gradient in a sample. Soft-x-ray microscopy using an SZP as a single element objective lens was demonstrated through the imaging of a 1 microm circular aperture at a wavelength of 2.73 nm(454 eV). A regular zone plate, a charge 1 SZP, and a charge 2 SZP were fabricated using electron beam lithography and were used as the imaging optic in the microscopy setup. The charge 1 and charge 2 SZP images exhibited isotropic edge enhancement as a result of radial Hilbert filtering.

Single-element objective lens for soft x-ray differential interference contrast microscopy

High-resolution soft x-ray differential interference contrast (DIC) imaging was demonstrated through the use of a single-element objective, the XOR pattern, in a full-field soft x-ray microscope. DIC images of the magnetic domains in a 59 nm thick amorphous Gd25Fe75 layer were obtained and magnetic phase contributions were directly imaged. With its elemental, chemical, and magnetic specificity, compatibility with various sample environments, and ease of implementation, we expect this soft x-ray DIC technique to become one of the standard modes of operation for existing full-field soft x-ray microscopes.

Characterization of x-ray phase vortices by ptychographic coherent diffractive imaging

We have characterized the x-ray phase vortices generated at the focal spot of various spiral Fresnel zone plates with an outermost zone width of Δr=50 nm. The complex-valued wavefields of phase vortices as small as 50 nm in size (FWHM) and several topological charges were reconstructed using ptychographic coherent diffractive imaging. The reconstructed focal spots demonstrate good agreement with the theoretically expected wavefields and diffraction-limited focusing.

Imaging at the Nanoscale With Practical Table-Top EUV Laser-Based Full-Field Microscopes

The demonstration of table-top high average power extreme-ultraviolet (EUV) lasers combined with the engineering of specialized optics has enabled the demonstration of full-field microscopes that have achieved tens of nanometer spatial resolution. This paper describes the geometry of the EUV microscopes tailored to specific imaging applications. The microscope illumination characteristics are assessed and an analysis on the microscopes spatial resolution is presented. Examples of the capabilities of these table-top EUV aerial microscopes for imaging nanostructures and surfaces are presented.

Coherent imaging at FLASH

We have carried out high-resolution single-pulse coherent diffractive imaging at the FLASH free-electron laser. The intense focused FEL pulse gives a high-resolution low-noise coherent diffraction pattern of an object before that object turns into a plasma and explodes. In particular we are developing imaging of biological specimens beyond conventional radiation damage resolution limits, developing imaging of ultrafast processes, and testing methods to characterize and perform single-particle imaging.

Focal Spot and Wavefront Sensing of an X-Ray Free Electron laser using Ronchi shearing interferometry

The Linac Coherent Light Source (LCLS) is an X-ray source of unmatched brilliance, that is advancing many scientific fields at a rapid pace. The highest peak intensities that are routinely produced at LCLS take place at the Coherent X-ray Imaging (CXI) instrument, which can produce spotsize at the order of 100 nm, and such spotsizes and intensities are crucial for experiments ranging from coherent diffractive imaging, non-linear x-ray optics and high field physics, and single molecule imaging. Nevertheless, a full characterisation of this beam has up to now not been performed. In this paper we for the first time characterise this nanofocused beam in both phase and intensity using a Ronchi Shearing Interferometric technique. The method is fast, in-situ, uses a straightforward optimization algoritm, and is insensitive to spatial jitter.

Soft x-ray microscopy

Summary form only given. Soft X-ray microscopy is at the forefront of research with spatial resolution approaching 10 nm, and wide ranging applications to the physical and life sciences, including the dynamics of magnetic nanostructures, three-dimensional biotomography at the sub-cellular level, elemental and chemically specific environmental studies. Examples of recent work are shown below in figures 1-3. Figure 1 shows a general layout of the soft X-ray microscope XM-1 at the Advanced Light Source (ALS) synchrotron facility at Lawrence Berkeley National Laboratory. Figure 2 shows an image, at 15 nm spatial resolution, of nanomagnetic structures in a CoCrPt alloy as revealed by X-ray magnetic circular dichroism (XMCD) using synchrotron radiation tuned to the cobalt L3-edge at 778 eV (1.59 nm wavelength). Figure 3 shows a natural contrast tomographic reconstruction of a whole yeast cell imaged in the water window at 500 eV (2.4 nm wavelength).

Movies At The Nanoscale Using Extreme Ultraviolet Laser Light

We report on the first demonstration of stop-motion imaging with ~50 nm spatial resolution using an extreme ultraviolet laser. Images of an AFM tip resonating at ~270 kHz were acquired with 1 ns temporal resolution.