Coherent diffraction imaging

<p>Coherent diffractive imaging (CDI)  a computational microscopy method that reconstructs images from coherent diffraction patterns without the use of lenses. It was first experimentally demonstrated in 1999 by <a href="/facts/Jianwei_Miao/ktr1lsll">Miao</a> and collaborators using synchrotron X-rays and iterative phase retrieval. CDI has been applied to image structures such as nanotubes, nanocrystals, porous nanocrystalline layers, defects, potentially proteins, and more. 
In CDI, a highly coherent beam of <a href="/facts/X-rays/wseP79cN">X-rays</a>, <a href="/facts/Electron/L0KBo5cW">electrons</a> or other wavelike particle or photon is incident on an object. The beam scattered by the object produces a <a href="/facts/Diffraction_pattern/Mk80xXHT">diffraction pattern</a> downstream which is then collected by a detector. This recorded pattern is then used to reconstruct an image via an iterative feedback algorithm. Effectively, the objective lens in a typical microscope is replaced with software to convert from the reciprocal space diffraction pattern into a real space image. The advantage in using no lenses is that the final image is <a href="/facts/Optical_aberration/YIqd9cA8">aberration</a>–free and so resolution is only diffraction and dose limited (dependent on <a href="/facts/Wavelength/kcJU0ymz">wavelength</a>, aperture size and exposure). Applying a simple inverse <a href="/facts/Fourier_transform/XXhKJtc8">Fourier transform</a> to information with only intensities is insufficient for creating an image from the diffraction pattern due to the missing phase information. This is called the <a href="/facts/Phase_problem/VU8SfTCX">phase problem</a>.
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Coherent diffraction imaging open-in-new

Coherent diffraction imaging