The peculiar properties of quantum optical states represent a new resource for innovative imaging schemes, as sub shot noise imaging or quantum illumination. Here we present in detail two works realized in INRIM. The first involves exploiting entanglement to enhance the imaging of a pure phase object in a non-interferometric setting. This wide-field method, based on the "transport of intensity equation", provides the absolute value of the phase without prior knowledge of the object. It does not require spatial and temporal coherence of the incident light. Besides improving image quality at a fixed number of photons, we demonstrate a clear reduction of the uncertainty in the quantitative phase estimation. This research also paves the way for applications at different wavelengths, e.g., x-ray imaging, where reducing the photon dose is of utmost importance. Then, we demonstrate a novel imaging technique, named Light Field Ghost Imaging, which exploits light correlations and light field imaging principles to enable overcome the limitations of ghost imaging in a wide range of applications. Notably, our technique removes the requirement to have prior knowledge of the object distance allowing us to refocus in post-processing and to perform 3D imaging while retaining all the benefits of GI protocols.
The peculiar properties of quantum optical states represent a new resource for innovative imaging schemes, as sub shot noise imaging or quantum illumination. Here we present in detail two works realized in INRIM. The first involves exploiting entanglement to enhance the imaging of a pure phase object in a non-interferometric setting. This wide-field method, based on the "transport of intensity equation", provides the absolute value of the phase without prior knowledge of the object. It does not require spatial and temporal coherence of the incident light. Besides improving image quality at a fixed number of photons, we demonstrate a clear reduction of the uncertainty in the quantitative phase estimation. This research also paves the way for applications at different wavelengths, e.g., x-ray imaging, where reducing the photon dose is of utmost importance. Then, we demonstrate a novel imaging technique, named Light Field Ghost Imaging, which exploits light correlations and light field imaging principles to enable overcome the limitations of ghost imaging in a wide range of applications. Notably, our technique removes the requirement to have prior knowledge of the object distance allowing us to refocus in post-processing and to perform 3D imaging while retaining all the benefits of GI protocols.
Quantum entanglement and squeezing have significantly improved phase estimation and imaging in interferometric settings beyond the classical limits. However, for a wide class of non-interferometric phase imaging/retrieval methods vastly used in the classical domain, e.g., ptychography and diffractive imaging, a demonstration of quantum advantage is still missing. Here, we fill this gap by exploiting entanglement to enhance imaging of a pure phase object in a non-interferometric setting, only measuring the phase effect on the free-propagating field. This method, based on the so-called "transport of intensity equation", is quantitative since it provides the absolute value of the phase without prior knowledge of the object and operates in wide-field mode, so it does not need time-consuming raster scanning. Moreover, it does not require spatial and temporal coherence of the incident light. Besides a general improvement of the image quality at a fixed number of photons irradiated through the object, resulting in better discrimination of small details, we demonstrate a clear reduction of the uncertainty in the quantitative phase estimation. Although we provide an experimental demonstration of a specific scheme in the visible spectrum, this research also paves the way for applications at different wavelengths, e.g., X-ray imaging, where reducing the photon dose is of utmost importance.
The peculiar properties of quantum optical states represent a new resource for innovative imaging schemes, as sub shot noise imaging or quantum illumination. In particular, quantum entanglement and squeezing have significantly improved phase estimation and imaging in interferometric settings beyond the classical limits. In this proceeding, after a general introduction, I will describe part of the recent work on quantum imaging performed in INRIM concerning phase imaging and light field ghost imaging.
ABSTRACT We review our last results in the field of quantum imaging obtained at INRIM Keywords: Quantum Imaging, Entanglement, Quantum Correlations, Sub shot noise measurements 1. INTRODUCTION Quantum properties of the optical field represent a resource of the utmost relevance for the development of quantum technologies, allowing unprecedented results in disciplines ranging from quantum information and metrology to quantum imaging. In particular, in the last case various protocols have been proposed ranging from ghost imaging [1,2], to quantum illumination [3] and sub-shot-noise quantum imaging [4]. Sub-shot-noise measurements with quantum optical states (for example exploiting the quantum correlations of Parametric Down Conversion (PDC) emission) provide the possibility of the detection of weak objects, a task that could have important practical applications. A little more in detail the principle of this technique is to take advantage of the correlation in the noise of two conjugated branches of PDC emission: in fact, s ubtracting the noise measured on one branch from the image of a weak object obtained in the other branch, the image of the object, previously hidden in the noise, could be restored. A schematic implemen tation of this protocol is depicted in Figure 1. On the other hand, ghost imaging technique allows to retrieve information about the object using spatial resolution detector from light (one arm of correlated beams) that does not interact directly with the object, whereas the photons transmitted thr ough (or reflected by) the object are registered by a bucket detector, which does not resolve the shape of the object.
Quantum correlation, such as entanglement and squeezing have shown to improve phase estimation in interferometric setups on one side, and non-interferometric imaging scheme of amplitude object on the other. In the last case, quantum correlation among a pair of beams leads to a sub-shot-noise readout of the image intensity pattern, where weak details, otherwise hidden in the noise, can be appreciated. In this paper we propose a technique which exploits entanglement to enhance quantitative phase retrieval of an object in a non-interferometric setting, i.e only measuring the propagated intensity pattern after interaction with the object. The method exploits existing technology, it operates in wide field mode, so does not require time consuming raster scanning and can operate with small spatial coherence of the incident field. This protocol can find application in optical microscopy and X-ray imaging, reducing the photon dose necessary to achieve a fixed signal-to-noise ratio.
G.Ortolano,A.Paniate,P.Boucher,C.Napoli,S.Soman,S.Pereira,I.Ruo Berchera,M.Genovese The peculiar properties of quantum optical states represent a new resource for innovative imaging schemes [1], as sub-shot noise imaging [2] or quantum illumination [3]. Here, after a general introduction, we present a work where photon number entanglement is exploited to enhance imaging of a pure phase object in a non-interferometric setting. Our method provides the absolute value of the phase without prior knowledge of the object operating in wide-field mode, so it does not need time-consuming raster scanning. Besides a general improvement of the image quality at a fixed number of photons irradiated through the object, we demonstrate a clear reduction of the uncertainty in the quantitative phase estimation. Significant application, in particular in biology, can be envisaged. [1] M.Genovese, J.of Optics, 18 (2016) 073002 [2] G.Brida et al., Nat.Phot. 4, 227 (2010). N.Samantaray et al. Light: Sc.&App.(2017) 6, e17005 [3] E.Lopaeva et al.,PRL 110, 153603 (2013)
Abstract In previous years the possibility of creating and manipulating quantum states of light has paved the way for the development of new technologies exploiting peculiar properties of quantum states, such as quantum information, quantum metrology and sensing, quantum imaging, etc. In particular quantum imaging addresses the possibility of overcoming limits of classical optics by using quantum resources such as entanglement or sub-Poissonian statistics. Albeit, quantum imaging is a more recent field than other quantum technologies, e.g. quantum information, it is now mature enough for application. Several different protocols have been proposed, some of them only theoretically, others with an experimental implementation and a few of them pointing to a clear application. Here we present a few of the most mature protocols ranging from ghost imaging to sub shot noise imaging and sub-Rayleigh imaging.