Scientists create brightest, sharpest and fastest x-ray hologramsAugust 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)
Tags: apertures, atomic motions, bacterium, berkeley national laboratory, electron beam, energys, free electron laser, free electron lasers, german researchers, holograms, lawrence berkeley national laboratory, light source, lithographic reproduction, marchesini, micrometers, nanometer resolution, nanoscale objects, pinhole camera, time scale, x ray