Researchers at the Stanford Synchrotron Radiation Laboratory (SSRL) and the German laboratory BESSY have crafted a versatile and stunningly effective technique to take x-ray images of tiny variations and lightning-quick changes in materials a thousand times smaller than the thickness of a strand of hair. Their work merits the cover of the December 16 issue of Nature. Researchers Jan Lüning of SSRL, Stefan Eisebitt of BESSY and their colleagues demonstrated the first direct imaging technique - lensless x-ray holography - that will work at the world's first x-ray free electron laser, the Linac Coherent Light Source (LCLS), slated to open at SLAC in 2009. Lensless imaging opens the door for "single shot" pictures at LCLS using just one pulse of x-ray light to capture a clear picture of ultra-fast action occurring on ultra-small length scale.

In the demonstration experiment at BESSY the team recorded an image revealing the randomly organized "north" and "south" magnetic regions of a cobalt-platinum film to a spatial resolution of 50 nanometers (50 billionths of a meter). Because the technique uses no lenses, lensless imaging has the potential to take direct images with 10 times better spatial resolution than achievable with current x-ray lenses. The technique works by shining a coherent beam of x-ray light through two adjacent holes: one containing the sample to be studied, the other a tiny "reference" hole. The scattered light from both holes overlays to form a single, holographic diffraction pattern. Holography not only maps the intensities of the light, as do normal diffraction patterns, it also encodes information about the phases of the light that is otherwise intrinsically lost. The information is decoded by applying a powerful mathematical procedure known as Fourier transformation, yielding a complete image of the sample.

The work of the SSRL authors is supported by the U.S. Department of Energy, Office of Basic Energy Sciences.

To learn more about this research see the full scientific highlight at:
http://www-ssrl.slac.stanford.edu/research/highlights_archive/lensless.html

Lensless imaging of magnetic nanostructures by X-ray spectro-holography S. Eisebitt, J. Lüning, W. F. Schlotter, M. Lörgen, O. Hellwig, W. Eberhardt, J. Stöhr, Nature 432, 885 (2004) http://www.nature.com