Scientists create brightest, sharpest and fastest x-ray holograms

August 2nd, 2008 - 3:04 pm ICT by ANI  

London, August 2 (ANI): An international team of U.S. and German researchers has produced two of the brightest and sharpest x-ray holograms of microscopic objects ever made, with the help of an approach they claim is thousands of times more efficient than previous x-ray-holographic methods.

This advancement is a result of the efforts of experts associated with the Advanced Light Source (ALS) at the U.S. Department of Energys Lawrence Berkeley National Laboratory, and at FLASH, the free-electron laser in Hamburg.

The researchers have revealed that their approach is inspired by the pinhole camera, a technique known since ancient times.

Our purpose was to explore methods of making images of nanoscale objects on the time scale of atomic motions, a length and time regime that promises to become accessible with advances in free-electron lasers, says Stefano Marchesini of the ALS, who led the research.

The technique we used is called massively parallel x-ray Fourier-transform holography, with coded apertures. What inspired me to try this approach was the pinhole camera, the researchers add.

The x-ray hologram made at ALS was of Leonardo da Vincis famous drawing Vitruvian Man, a lithographic reproduction less than two micrometers square, etched with an electron-beam nanowriter.

According to the researchers, the hologram required a five-second exposure, and had a resolution of 50 nanometres.

The hologram made at FLASH was of a single bacterium called Spiroplasma milliferum, which was made at 150-nanometer resolution, and computer-refined to 75 nanometers.

It, however, required an exposure to the beam of just 15 femtoseconds.

The values for the two holograms are among the best ever reported for micron-sized objects.

The researchers believe that technologies already established may help push resolutions they have obtained to only a few nanometres, or even better by using computer refinement.

Imaging with coherent x-rays will be a key technique for developing nanoscience and nanotechnology, and massively parallel holography will be an enabling tool in this quest, write the researchers in their Nature Photonics article. (ANI)

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