In ghost imaging (GI) an object can be 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, compared with conventional photography, images of sub-Rayleigh resolution may be obtained even with poor illumination in a highly scattering medium. However, technical difficulties hampered the development of x-ray GI until 2016, when it was first demonstrated on a synchrotron. Last year, 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 at ultra-low radiation levels. Imaging on the order of single photons has even been achieved, thus radiation damage in medical diagnosis could be greatly reduced with this new method.[1]
[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)

After graduating from Peking Univ. in 1968 Ling-An Wu was assigned to Jiheng State Farm, Hebei, then in 1971 to IoP CAS. From 1981-87 she was on leave at the Univ. of Texas at Austin where she obtained a Ph.D. under H.J. Kimble; her thesis on "Squeezed states of light from an optical parametric oscillator" has been incorporated into textbooks, and its publication in Phys. Rev. Lett. was amongst the 2015 Physical Review Journals Celebrate the International Year of Light selected papers. After her return, she was the first in China to demonstrate quantum key distribution in free space and in fiber in 1995 and 2000, respectively, then started developing true random number generators, single-photon detectors, and “ghost” imaging. She was the first to realize ghost imaging with true thermal light, natural sunlight, and last year with ultralow dosage X-rays on a simple tabletop setup. Officially retired in 2009 she is still actively working and has been teaching at University of CAS since 2015. To date she has published more than 170 journal papers with ~4000 citations, and 16 patents. In addition to many awards she received, she got 2018 Optical Society of America Diversity & Inclusion Advocacy Recognition Award recently.