Marco Genovese

Experimental Reconstruction of Photon Statistics without Photon Counting

Experimental reconstructions of photon number distributions of both continuous-wave and pulsed light beams are reported. Our scheme is based on on/off avalanche photo-detection assisted by maximum-likelihood estimation and does not involve photon counting. Reconstructions of the distribution for both semiclassical and quantum states of light are reported for single-mode as well as for multi-mode beams.

Systematic analysis of signal-to-noise ratio in bipartite ghost imaging with classical and quantum light

We present a complete and exhaustive theory of signal-to-noiseratio in bipartite ghost imaging with classical (thermal) and quantum (twin beams) light. The theory is compared with experiment for both twin beams and thermal light in a certain regime of interest.

Measurement of Sub-Shot-Noise Spatial Correlations without Background Subtraction

In this Letter we present the measurement of sub-shot-noise spatial correlations without any subtraction of background, a result paving the way to realize sub-shot-noise imaging of weak objects.

Twin-photon techniques for photo-detector calibration

The aim of this review paper is to enlighten some recent progresses in quantum optical metrology in the part of quantum efficiency measurements of photo-detectors performed with bi-photon states. The intrinsic correlated nature of entangled photons from Spontaneous Parametric Down Conversion phenomenon has opened wide horizons to a new approach for the absolute measurement of photo-detector quantum efficiency, outgoing the requirement for conventional standards of optical radiation; in particular the simultaneous feature of the creation of conjugated photons led to a well known technique of coincidence measurement, deeply understood and implemented for standard uses. On the other hand, based on manipulation of entanglement developed for Quantum Information protocols implementations, a new method has been proposed for quantum efficiency measurement, exploiting polarisation entanglement in addition to energy-momentum and time ones, that is based on conditioned polarisation state manipulation. In this review, after a general discussion on absolute photo-detector calibration, we compare these different methods, in order to give an accurate operational sketch of the absolute quantum efficiency measurement state of the art.

An application of two-photon entangled states to quantum metrology

Abstract Besides many interesting applications to the study of the foundations of quantum mechanics, entangled states are now assuming much relevance for some practical applications. In particular, we discuss the use of two-photon entangled states produced in parametric down conversion for absolute quantum efficiency calibration of photodetectors, in the photon counting regime.

Quantum characterization of superconducting photon counters

We address the quantum characterization of photon counters based on transition-edge sensors (TESs) and present the first experimental tomography of the positive operator-valued measure (POVM) of a TES. We provide the reliable tomographic reconstruction of the POVM elements up to 11 detected photons and M?=?100 incoming photons, demonstrating that it is a linear detector.

Statistical estimation of the efficiency of quantum state tomography protocols.

Y u. I. Bogdanov, G.Brida,M.Genovese, S. P. Kulik, E. V. Moreva, A. P. Shurupov 1 Institute of Physics and Technology, Russian Academy of Sciences, Moscow, Russia 2 INRIM, I-10135, Torino, Italy 3 Faculty of Physics, Moscow State University, 119992, Moscow, Russia 4 Moscow National Research Nuclear University ”MEPHI”, Russia and 5 Dipartimento di Fisica, Politecnico di Torino, I-10129, Torino, Italy (Dated: February 18, 2010)

Detection of multimode spatial correlation in PDC and application to the absolute calibration of a CCD camera

We propose and demonstrate experimentally a new method based on the spatial entanglement for the absolute calibration of analog detectors. The idea consists on measuring the sub-shot-noise intensity correlation between two branches of parametric down conversion, containing many pairwise correlated spatial modes. We calibrate a scientific CCD camera and a preliminary evaluation of the uncertainty indicates the metrological interest of the method.

Beating the Abbe diffraction limit in confocal microscopy via nonclassical photon statistics.

We experimentally demonstrate quantum enhanced resolution in confocal fluorescence microscopy exploiting the nonclassical photon statistics of single nitrogen-vacancy color centers in diamond. By developing a general model of superresolution based on the direct sampling of the kth-order autocorrelation function of the photoluminescence signal, we show the possibility to resolve, in principle, arbitrarily close emitting centers.

Experimental realization of a low-noise heralded single-photon source.

We present a heralded single-photon source with a much lower level of unwanted background photons in the output channel by using the herald photon to control a shutter in the heralded channel. The shutter is implemented using a simple field programable gate array controlled optical switch.