We report an experimental proof of principle for ghost imaging in the hard x-ray energy range. We used a synchrotron x-ray beam that was split using a thin crystal in Laue diffraction geometry. With an ultra-fast imaging camera, we were able to image x-rays generated by isolated electron bunches. At this time scale, the shot noise of the synchrotron emission process is measurable as speckles, leading to speckle correlation between the two beams. The integrated transmitted intensity from a sample located in the first beam was correlated with the spatially resolved intensity measured in the second, empty, beam to retrieve the shadow of the sample. The demonstration of ghost imaging with hard x-rays may open the way to protocols to reduce radiation damage in medical imaging and in non-destructive structural characterization using Free Electron Lasers.Ghost imaging, in its basic form, is the technique of indirectly imaging a sample by using the correlation between the intensity recorded at two detectors illuminated by spatially separated correlated beams [1]. A bucket detector measures the total intensity transmitted (or scattered) by a sample, placed in one of the beams. The sample image is then retrieved by correlating the output of the bucket detector with a pixel array detector located in the other beam, namely the one that has not directly interacted with the sample. Initially demonstrated with entangled photon pairs [2], ghost imaging was subsequently performed using correlation between classical coherent light beams [3]. The protocol was shown to be very robust, leading to experimental studies on ghost imaging using pseudo-thermal light [4][5][6], true thermal sources [7], and eventually computational ghost imaging [8], where a computer-controlled spatial light modulator generates a series of known illuminating fields, altogether removing the need for imaging the empty beam. Of relevance for this paper is also a very recent demonstration of Fourier transform ghost imaging using speckle fields generated with partially coherent synchrotron x-rays [9]. At the heart of thermal ghost imaging is the speckle correlation in the intensity fluctuations of the illuminating beam. The speckles can be produced either by nearfield diffraction of a coherent beam by a slowly moving diffracting object [4-6, 9], or taking advantage of the natural fluctuations of true thermal light [7], as in the Hanbury Brown-Twiss (intensity) interferometer [10]. In this Letter we use the latter mechanism to produce the first proof of principle demonstration of hard x-ray direct ghost imaging using synchrotron emission from an undulator in a third generation synchrotron storage ring. Synchrotron emission from an ultra-relativistic electron bunch provides a natural thermal source of hard x-rays. Intensity correlation x-ray experiments, proposed as far back as 1975 [11] (see also [12]), were employed several times for coherence characterization of synchrotron [13][14][15] and x-ray Free Electron Laser (FEL) [16] beams. To date though, x-ray spec...

A practical experimental procedure for transmission X-ray ghost imaging (XGI) using synchrotron light is presented. The authors demonstrate the method, discuss data acquisition and analysis, and measure the point-spread function of an XGI system. The generalization of the methods for future experiments is also discussed.

Ghost tomography using single-pixel detection extends the emerging field of ghost imaging to three dimensions, with the use of penetrating radiation. In this work, a series of spatially random x-ray intensity patterns is used to illuminate a specimen in various tomographic angular orientations with only the total transmitted intensity being recorded by a single-pixel camera (or bucket detector). The set of zero-dimensional intensity readings, combined with knowledge of the corresponding two-dimensional illuminating patterns and specimen orientations, is sufficient for three-dimensional reconstruction of the specimen. The experimental demonstration of ghost tomography is presented here using synchrotron hard x-rays. This result expands the scope of ghost imaging to encompass volumetric imaging ( i.e. , tomography), of optically opaque objects using penetrating radiation. For hard x-rays, ghost tomography has the potential to decouple image quality from dose rate as well as image resolution from detector performance.

Scanning X-ray fluorescence microscopy (XFM) is a particularly useful method for studying the spatial distribution of trace metals in biological samples. Here we demonstrate the utility of combining coherent diffractive imaging (CDI) with XFM for imaging biological samples to simultaneously produce high-resolution and high-contrast transmission images and quantitative elemental maps. The reconstructed transmission function yields morphological details which contextualise the elemental maps. We report enhancement of the spatial resolution in both the transmission and fluorescence images beyond that of the X-ray optics. The freshwater diatom Cyclotella meneghiniana was imaged to demonstrate the benefits of combining these techniques that have complementary contrast mechanisms.

A simultaneous, contextual experimental demonstration of the two processes of cloning an input qubit |Ψ >and of flipping it into the orthogonal qubit |Ψ ⊥ > is reported. The adopted experimental apparatus, a Quantum-Injected Optical Parametric Amplifier (QIOPA) is transformed simultaneously into a Universal Optimal Quantum Cloning Machine (UOQCM) and into a Universal NOT quantum-information gate. The two processes, indeed forbidden in their exact form for fundamental quantum limitations, will be found to be universal and optimal, i.e. the measured fidelity of both processes F < 1 will be found close to the limit values evaluated by quantum theory. A contextual theoretical and experimental investigation of these processes, which may represent the basic difference between the classical and the quantum worlds, can reveal in a unifying manner the detailed structure of quantum information. It may also enlighten the yet little explored interconnections of fundamental axiomatic properties within the deep structure of quantum mechanics. PACS numbers:03.67.-a, 03.65.Ta, 03.65.Ud