Novel X-ray imaging technique allows nanoscale world to be seen in real space

Scientists at German and American synchrotron facilities have recently reported the significance of lensless imaging in achieving extremely high-spatial resolution. Although lenses are generally good at obtaining a magnified image of a sample, they also unfortunately introduce aberrations in the image, which ultimately limit the spatial resolution obtainable. In principle, one can form an image without a lens, by means of a coherent scattering experiment. The challenge is to solve the so-called phase problem. The team recently developed a new approach to X-ray holography, realizing a Fourier transform holography geometry by use of a micro- and nanostructured mask. Special contrast mechanisms can be exploited by resonant soft x-ray scattering and, in the experiment at BESSY, they recorded an image revealing the randomly organized "north" and "south" magnetic regions of a cobalt-platinum film to a spatial resolution of 50 nm, which is 10 times better than that achievable with conventional X-ray focusing optics. In the future, the technique will be used as a method for ultra-fast stroboscopic imaging on a femtosecond time scale using an X-ray free electron laser such as the Linac Coherent Light Source (LCLS), for example, which is expected to open at Stanford in 2009. For more information, see the paper, "Lensless imaging of magnetic nanostructures by X-ray spectro-holography", S. Eisebitt et al., Nature, 432, 885-888 (2004).