High numerical aperture tabletop soft x-ray diffraction microscopy with 70-nm resolution
- Richard L. Sandberg*,
- Changyong Song†,
- Przemyslaw W. Wachulak‡,
- Daisy A. Raymondson*,
- Ariel Paul*,
- Bagrat Amirbekian†,
- Edwin Lee†,
- Anne E. Sakdinawat§,
- Chan La-O-Vorakiat*,
- Mario C. Marconi‡,
- Carmen S. Menoni‡,
- Margaret M. Murnane*,¶,
- Jorge J. Rocca‡,
- Henry C. Kapteyn*, and
- Jianwei Miao†
- *Department of Physics and JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, CO 80309-0440;
- †Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, CA 90095;
- ‡Department of Electrical and Computer Engineering, Colorado State University, 1320 Campus Delivery, Fort Collins, CO 80523-1320; and
- §Center for X-ray Optics at Lawrence Berkeley National Laboratory and University of California at Berkeley/University of California at San Francisco Joint Graduate Group in Bioengineering, 1 Cyclotron Road, Berkeley, CA 94720
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Contributed by Margaret M. Murnane, November 14, 2007 (received for review October 25, 2007)
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Fig. 1.Setup of the tabletop soft x-ray diffraction microscope. A coherent soft x-ray beam is produced by high-harmonic generation or by spatially filtering the emission from a capillary discharge laser in an Ar-filled hollow waveguide. The beam is gently focused by a multilayer mirror pair onto the sample, and the diffraction pattern is collected on an x-ray CCD. A moveable beam block allows for brighter portions of the diffraction pattern to be blocked to avoid saturating the CCD when acquiring the highest angle diffracted light. ROC, radius of curvature.
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Fig. 2.Curvature correction in high numerical aperture lensless imaging. (a and d) Coherent soft x-ray diffraction pattern at 47-nm wavelength (in transmission) before and after curvature correction (maximum momentum transfer of 0.166 nm−1 at the edge of the CCD). (b and e) Magnified diffraction pattern at high diffraction angles showing the radial blurring near the upper-right edge in b, which is absent in e. (c and f) Reconstructed image of waving stick figure without and with curvature correction. The lower width and increased sharpness of the curvature-corrected stick-girl image can be seen in the lineouts shown in c and f Insets.
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Fig. 3.Lensless imaging with coherent soft x-ray laser beams at 47 nm. (a) Reflection image of the waving stick-figure sample by using an SEM. (Scale bar, 1 μm.) (b) Coherent soft x-ray diffraction pattern (in transmission) after curvature correction (maximum momentum transfer of 0.166 nm−1 at the edge of the CCD). (c) Reconstructed image with curvature correction. (d) Lineout of the image along the legs (Inset), verifying a resolution of 71 nm.
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Fig. 4.Lensless imaging by using coherent high-harmonic beams at 29 nm. (a) Reflection image of the sample using an SEM. (Scale bar, 1 μm.) (b) Coherent soft x-ray diffraction pattern (in transmission) after curvature correction (maximum momentum transfer of 0.134 nm−1 at the edge of the CCD). (c) Reconstructed image. (d) Lineout of the image along the legs (Inset), demonstrating a resolution of 94 nm.
Footnotes
- ¶To whom correspondence should be addressed. E-mail: murnane{at}jila.colorado.edu
- © 2007 by The National Academy of Sciences of the USA
