Panoramic images are captivating in any form, with their wide field of view and extremely high resolution. Now, SSRL scientists have demonstrated a new x-ray holographic technique for imaging wide areas of a nanoscale sample without losing resolution. The results were published in the November 2007 edition of the journal Optics Letters.

A similar technique was first demonstrated at Stanford over 50 years ago using light of visible wavelengths as a means of improving holographic images distorted by atmospheric disturbances. With x-rays, however, it is the finite size of the pixels in the detector that blurs resolution, which in a hologram translates to a smaller field of view in the reconstructed image. To overcome this limitation, the team strategically arranged a collection of reference points on the sample to increase the effective field of view, which counters the smearing otherwise caused by the detector.

The team used the soft x-ray coherent scattering capabilities of Beam Line 5-2 (which has now been moved to a new location and is BL13-3) to image a nanostructured, 1 micron-thick gold film sample. Four individual arrow shapes spanning one fifth of a millimeter were milled through the film, with a strategically placed reference point next to each arrow. The reconstructed image successfully showed all four arrows with 50-nanometer resolution.

The new technique could also prove particularly useful for studying ultrafast processes using x-ray free electron lasers such as the Linac Coherent Light Source.

W. F. Schlotter, J. Lüning, R. Rick, K. Chen, A. Scherz, S. Eisebitt, C. M. Günther, W. Eberhardt, O. Hellwig, J. Stöhr, "Extended field of view soft x-ray Fourier transform holography: toward imaging ultrafast evolution in a single shot" Optics Letters, 32 (21) p3110 (2007)

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