Full-field phase contrast imaging with coded aperture and laboratory X-ray source

Phase contrast X-ray imaging is a promising method for low Z samples which cannot always be properly imaged by conventional absorption and scattering imaging. Recently Professor R. D. Speller (University College London) and his colleagues reported a novel way using a laboratory X-ray source outfitted with a pair of coded apertures; one in front of the sample for imaging and one behind it. They were offset slightly to remove scattering background. Readers might be aware that the method is quite similar to X-ray Talbot interferometry (for example, see the previous news article, "Micro-structure imaging using visibility contrast", No.5, Vol. 39 (2010)), when a 2D grating is used as a coded-aperture. The technique could open up many interesting opportunities through its application to a wide range of fields, such as nano-bio technologies, because the experiments can be done with an ordinary incoherent X-ray source. For more information, see the paper, "Noninterferometric phase-contrast images obtained with incoherent x-ray sources", A. Olivo et al., Appl. Optics, 50, 1765 (2011).