Possibilities for X-Ray Holography Using Synchrotron Radiation

Howells, M. R.

doi:10.1007/978-3-540-38833-3_37

Cited by 8 publications

(3 citation statements)

References 14 publications

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“…1989), which again is much larger than the associated wavelength (1-10 A). Furthermore, experiments with X-ray holography (Howells 1984) suggest that the degree of coherence for a synchrotron source is not insignificant. Placing a c c d array in the far-field would not be experimentally difficult, and by using the Wigner deconvolution all the effects of the poor quality zone-plate could be accounted for as well as allowing full use of the high-angle diffraction data.…”

Section: Discussionmentioning

confidence: 99%

The theory of super-resolution electron microscopy via Wigner-distribution deconvolution

Rodenburg

Bates

1992

Phil. Trans. R. Soc. Lond. A

225

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The theory of deconvolving the microdiffraction data-set available in a scanning transmission electron microscope or, equivalently, the set of all bright- and dark-field images available in a conventional transmission electron microscope to obtain super- resolution micrographs (which are not limited by the transfer function of the objective lens) is developed and described with reference to holography and other phase-retrieval schemes. By the use of a Wigner distribution, influences of the instrument function can be entirely separated from the information pertaining to the specimen. The final solution yields an unambiguous estimate of the complex value of the specimen function at a resolution which in theory is only limited by the electron wavelength. The faithfulness of the image processing is shown to be not seriously affected by specimen thickness or partial coherence in the illuminating beam. The inversion procedure is remarkably noise insensitive, implying that it should result in a robust and practicable experimental technique, though one that will require very large computing facilities.

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Section: Discussionmentioning

confidence: 99%

The theory of super-resolution electron microscopy via Wigner-distribution deconvolution

Rodenburg

Bates

1992

Phil. Trans. R. Soc. Lond. A

225

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“…5 ' Were we to try to put the resist even closer to the specimen, however, we would soon run into an information mapping mismatchloosely speaking, we must map Ns specimen pixels into Nd >> Ns detector pixels.9 A more detailed analysis of this point gives insight into the conditions needed for three-dimensional imaging. 52 In these initial explorations, we chose to work only with dry specimens, although hydrated specimens have been imaged by soft-x-ray microscopes. 3 The specimens, described below in Section 7, were placed on standard Formvar-coated electron microscope grids.…”

Section: Beam-line Optical Layoutmentioning

confidence: 99%

X-ray holographic microscopy using photoresists

et al. 1990

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Gabor x-ray holograms of biological specimens and of test objects that display <56-nm resolution are presented. This spatial resolution is more than an order of magnitude smaller than what has been achieved previously in x-ray holography. The holograms were recorded on photoresist using 2.57-nm soft x rays from the X-17t undulator at the National Syncrotron Light Source at Brookhaven National Laboratory. The processed photoresists were enlarged with an electron microscope and digitized using a scanning microdensitometer; the digitized holograms were reconstructed numerically. The exposure requirements were in good agreement with simple theory. The method offers promise as a technique for soft-x-ray microscopy.

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“…Thus, when the prospect of x-ray laser and synchrotron radiation sources with many orders of magnitude more coherent power appeared in the early 1980's, interest in x-ray holography revived. 6,7 Experimental programs were started at various centers, [8][9][10] using mostly undulator x-ray sources and polymer photoresist detectors, and these led to the achievement of submicronresolution reconstructed images at Brookhaven 11,12 and Orsay 13 and the demonstration of x-ray laser holography at Livermore. 14 High-resolution x-ray Fourier holography was also demonstrated for the first time by McNulty et al, 15,16 and the history of all these efforts was reviewed by Jacobsen.…”

Section: Introductionmentioning

confidence: 99%

X-ray holographic microscopy by means of photoresist recording and atomic-force microscope readout

1996

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We have reconstructed in-line (or Gabor) x-ray holograms at 40-50-nm resolution from a complex biological specimen. The holograms were recorded as a relief pattern on photoresist with use of 1.89-nm, soft x rays from the X1A undulator beam line at the National Synchrotron Light Source at Brookhaven National Laboratory. We have improved the resolution and the fidelity and simplified the experiment compared with earlier work by employing a special atomic-force microscope to examine and digitize the holograms. Following digitization the holograms were reconstructed numerically, allowing both the absorptive and phase-shifting properties of the reconstructed object to be mapped. A comparison of the reconstructed images with images obtained from visible light and transmission electron microscopes has been made to confirm the validity of the x-ray holographic technique. The method offers promise as a technique for soft-x-ray microscopy and diffraction tomography of dry and frozen hydrated specimens and for microscopy with pulsed x-ray sources.

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Possibilities for X-Ray Holography Using Synchrotron Radiation

Cited by 8 publications

References 14 publications

The theory of super-resolution electron microscopy via Wigner-distribution deconvolution

The theory of super-resolution electron microscopy via Wigner-distribution deconvolution

X-ray holographic microscopy using photoresists

X-ray holographic microscopy by means of photoresist recording and atomic-force microscope readout

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