Books
M. Genovese
Recent progresses in testing hidden variables models at IENGF
Progress in Experimental High Energy Physics Research, Nova
Science Publication, pgg. 333, 2005.
International and National Journals
G. Brida, M. Genovese, M.Gramegna, M. L. Rastello, M. Chekhova, L. Krivitsky
Single-photon detectors calibration by means of conditional polarisation rotation
Journal of Optical Society of America B, Vol. 22, no. 2, pp. 488-492, 2005.
We propose a new scheme for measuring the quantum efficiency of a single photon detection apparatus by using polarization-entangled states. The scheme consists of measuring the polarization of a member of a polarization-entangled pair after a 90o polarization rotation conditional to the detection of the correlated photon after polarization selection. We present experimental results obtained with this scheme compared with biphoton calibration. Our results show the interesting potentiality of the suggested scheme.
I. P. Degiovanni, I. Ruo Berchera, S. Castelletto, M. L. Rastello, F. A. Bovino, A. M. Colla, G. Castagnoli
Reply to "Comment on `Quantum dense key distribution"
Physical Review A, Vol. 71, no. 1, 016302, 2005.
In this Reply we propose a modified security proof of the quantum dense key distribution protocol, detecting also the eavesdropping attack proposed by Wójcik in his Comment [Wójcik, Phys. Rev. A 71, 016301 (2005)].
P. Fiorentin, P. Iacomussi, G. Rossi
Characterization and calibration of a CCD detector for light engineering
IEEE Transactions on Instrumentation and Measurement, Vol. 54, no. 1, pp. 171-177, 2005.
This paper describes the methodology developed for characterizing a commercial charge-coupled device (CCD) camera as a luminance meter for analyzing lighting systems and especially for measurements in road light plants. Today, several luminance meters based on commercial CCD cameras are on the market. They are very attractive for the lighting engineer: The availability of a high number of closely spaced small detectors (pixels) on a single chip permits analyses almost impossible with a traditional luminance meter. These commercial-industrial CCD cameras are sold at prices lower than scientific grade ones. They are factory equipped with a dedicated filter to reach the correct photopic sensitivity V(λ), and they are factory calibrated in luminance SI units. The main counterparts in using these cameras are in the difficulties to define the measurement accuracy and the influence of the environment luminance on the measured values of the framed scene, in the low resolution of their A/D converter (usually 8 or 12 bit), and the higher noise level (usually the CCD chip is not cooled). To reach the measurement accuracy required by lighting norms, it is necessary to characterize metrologically a camera and quantify all the possible external influences which could degrade its performances, in real measurement situations, and which could affect the measurement results. A carefully controlled measurement set up and operating procedure could limit the causes of errors and improve the accuracy of measurements obtained in operating conditions. In this way, the measurement uncertainties might be evaluated completely, and considerations on the results could suggest particular operating practices to limit the causes of error due to measurement setup and environmental conditions.
S. Castelletto, I. P. Degiovanni, G. Furno, V. Schettini, A. Migdall, M. Ware
Two-photon mode preparation and matching efficiency: definition, measurement, and optimization
IEEE Transactions on Instrumentation and Measurement, Vol. 54, no. 2, pp. 890-893, April 2005.
We investigate the coupling efficiency of parametric downconversion light (PDC) into single and multimode optical fibers as a function of the pump beam diameter, crystal length, and walk-off. We outline two different theoretical models for the preparation and collection of either single-mode or multimode PDC light (defined by, for instance, multimode fibers or apertures). Moreover, we define the mode-matching collection efficiency, important for realizing a single-photon source based on PDC output into a well-defined single mode. We also define a multimode collection efficiency that is useful for single-photon detector calibration applications.
G. Brida, M. Chekhova, M. Genovese, M. Gramegna, L. Krivitsky, M. L. Rastello
Absolute quantum efficiency measurements by means of conditioned polarization rotation
IEEE Transactions on Instrumentation and Measurement, Vol. 54, no. 2, pp. 898-900, April 2005.
We propose a new scheme for measuring the quantum efficiency of photon counting detectors by using correlated photons. The measurement technique is based on a 90o rotation of the polarization of one photon member of a correlated pair produced by parametric down-conversion, conditioned on the detection of the other correlated photon after polarization selection.We present experimental results obtained with this scheme.
M. Genovese
Research on hidden variable theories: a review of recent progresses
Physics reports - A Review Section of Physics Letters, Vol. 413, no. 6, pp. 319-396, 2005.
Quantum Mechanics (QM) is one of the pillars of modern physics: an impressive amount of experiments have confirmed this theory and many technological applications are based on it. Nevertheless, at one century since its development, various aspects concerning its very foundations still remain to be clarified. Among them, the transition from a microscopic probabilistic world into a macroscopic deterministic one and quantum non-locality. A possible way out from these problems would be if QM represents a statistical approximation of an unknown deterministic theory. This review is addressed to present the most recent progresses on the studies related to Hidden Variable Theories (HVT), both from an experimental and a theoretical point of view, giving a larger emphasis to results with a direct experimental application. More in details, the first part of the review is a historical introduction to this problem. The Einstein-Podolsky-Rosen argument and the first discussions about HVT are introduced, describing the fundamental Bell's proposal for a general experimental test of every Local HVT and the first attempts to realise it. The second part of the review is devoted to elucidate the recent progresses toward a conclusive Bell inequalities experiment obtained with entangled photons and other physical systems. Finally, the last sections are targeted to shortly discuss Non-Local HVT.
S. Castelletto, I. P. Degiovanni, V. Schettini, A. Migdall
Spatial and spectral mode selection of heralded single photons from pulsed Parametric Down-Conversion
Optics Express, Vol. 13, no. 18, pp. 6709-6722, 2005.
We describe an experiment in which photon pairs from a pulsed parametric down-conversion (PDC) source were coupled into single-mode fibers with heralding efficiencies as high as 70%. Heralding efficiency or mode preparation efficiency is defined as the probability of finding a photon in a fiber in a definite state, given the detection of its twin. Heralding efficiencies were obtained for a range of down-conversion beam-size configurations. Analysis of spatial and spectral mode selection, and their mutual correlation, provides a practical guide for engineering PDC-produced single photons in a definite mode and spectral emission band. The spectrum of the heralded photons were measured for each beam configuration, to determine the interplay between transverse momentum and spectral entanglement on the preparation efficiency.
A. Ghazi-Bellouati, A. Razet, J. Bastie, M.E. Himbert, I.P. Degiovanni, S. Castelletto, M.L. Rastello
Radiometric reference for weak radiations: comparison of methods
Metrologia 42 (4), pp. 271-277, 2005.
The parametric down conversion of photons generated in a non-linear crystal gives rise to two correlated photons. When associated with a system of coincidence counting, this phenomenon allows one to measure the quantum efficiencies of detectors working at a normal rate of photon counting, without the need for reference sources or detectors. At the Institut National de Métrologie (INM) (France), this method was implemented with the aim of developing a new standard detector for the absolute measurement of very weak radiation. The validation of this method is presented from an international comparison between the laboratories of the INM (France) and the Istituto Elettrotecnico Nazionale Galileo Ferraris (IENGF) (Italy) and from a comparison of methods at INM using the French national standard detector, the cryogenic radiometer.
M. Genovese
On tests of local realism by CP-violation parameters of K-0 mesons
European Physical Journal C 42 (1), pp. 25-28, 2005.
Recently various papers have proposed to test local realism (LR) by considering electroweak CP-violation parameters values in neutral pseudoscalar meson systems. Considering the large interest for a conclusive test of LR and the experimental accessibility to these tests, in this paper we critically consider these results showing how they, albeit very interesting, require anyway additional assumptions and therefore cannot be considered conclusive tests of LR.
M. Genovese
Limit quantum efficiency for violation of Clauser-Horne inequality for qutrits
Physical Review A 71 (5), 052314, 2005.
In this paper we present the results of numerical calculations about the minimal value of detection efficiency for violating the Clauser - Horne inequality for qutrits. Our results show how the use of non-maximally entangled states largely improves this limit respect to maximally entangled ones. A stronger resistance to noise is also found.
G. Zambra, A. Andreoni, M. Bondani, M. Gramegna, M. Genovese, G. Brida, A. Rossi, M.G.A. Paris
Experimental reconstruction of photon statistics without photon counting
Physical Review Letters 95 (6), 063602, 2005.
Experimental reconstructions of photon number distributions of both continuous-wave and pulsed light beams are reported. Our scheme is based on on/off avalanche photodetection 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 multimode beams.
M. Genovese, G. Brida, E. Cagliero, M. Gramegna, E. Predazzi
Review of recent experimental progresses in foundations of quantum mechanics and quantum
information achieved in parametric downconversion experiments at IENGF
Optics and Spectroscopy, Vol. 99, no. 2, pp. 170-180, 2005.
We review some recent experimental progresses concerning
Foundations of Quantum Mechanics and Quantum Information obtained
in Quantum Optics Laboratory "Carlo Novero" at IENGF.
More in details, after a short presentation of our polarization
entangled photons source (based on precise superposition of two
Type I PDC emission) and of the results obtained with it, we
describe an innovative double slit experiment where two degenerate
photons produced by PDC are sent each to a specific slit. Beyond
representing an interesting example of relation between visibility
of interference and "welcher weg" knowledge, this configuration
has been suggested for testing de Broglie-Bohm theory against
Standard Quantum Mechanics. Our results perfectly fit SQM results,
but disagree with dBB predictions.
Then, we discuss a recent experiment addressed to clarify the
issue of which wave-particle observables are really to be
considered when discussing wave particle duality. This experiments
realises the Agarwal et al. theoretical proposal, overcoming
limitations of a former experiment.
Finally, we hint to the realization of a high-intensity
high-spectral-selected PDC source to be used for quantum
information studies.
Conference Proceedings
G. Brida, E. Cagliero, M. Genovese, M. Gramegna, E. Predazzi
Recent progresses at IENGF on studies on quantum information
Proceedings of Quantum Communication and Quantum Imaging, ed. R.E. Meyers and Y. Shih, SPIE Proceedings Vol. 5893, p. 120, San Diego 2005.
P. Iacomussi, G. Rossi (oral session)
Glazing units characterization: a new integrating sphere system
Proceedings of the 12th International Metrology Congress, Lyon (France), June 2005 (cd rom).
Translucent glazing units are widely used in buildings to control and distribute the light in the environment. Unfortunately correct and really useful characterisation parameters and data usefull for studying quantitatively the real condition behaviour, are not easily achievable. The main problems arise from the optical properties of artefact itself and from the measurement devices that are often not completely appropriate. At IEN a new measurement set-up was designed and realized with enhanced performances and measurement capability.