High resolution, ultralow radiation “ghost” imaging with incoherent x-rays

In “ghost” imaging (GI) an object is imaged indirectly with a non-spatially resolving detector through intensity correlation computation. The first GI experiment was performed in 1995 with entangled photon pairs, then later it was shown that classical thermal light can also be used. In theory any wavelength is possible, and so GI has attracted great interest because images of sub-Rayleigh resolution may be obtained even with poor illumination in a highly scattering medium. However, due to technical difficulties x-ray GI was only first realized in 2016 with synchrotron radiation. In 2017, using a simple table-top discharge tube source we obtained images of planar and natural objects for the first time, with a much higher contrast-to-noise ratio compared to conventional x-ray imaging, and at ultra-low radiation levels on the order of single photons, thus radiation damage can be greatly reduced with our new method[1]. This work was reported in News in Depth in Science, and was selected as one of the 2018 Top Ten Advances in Optics in China. Recently, with a new modulation mask and deep learning algorithm we can now achieve a resolution of 10 m, which should be sufficient for practical medical diagnosis.[1] A.X. Zhang, Y.H. He, L.A. Wu, L.M. Chen and B.B. Wang, “Table-top X-ray Ghost Imaging with Ultra-Low Radiation”, Optica 5, 374 (2018).