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 detector. 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 statistical uncertainty indicates the metrological interest of the method

Analysis of the possibility of analog detectors calibration by exploiting Stimulated Parametric Down Conversion

Spontaneous parametric down conversion (SPDC) has been largely exploited as a tool for absolute calibration of photon-counting detectors, i.e detectors registering very small photon fluxes. In [J. Opt. Soc. Am. B 23, 2185 (2006)] we derived a method for absolute calibration of analog detectors using SPDC emission at higher photon fluxes, where the beam is seen as a continuum by the detector. Nevertheless intrinsic limitations appear when high-gain regime of SPDC is required to reach even larger photon fluxes. Here we show that stimulated parametric down conversion allow one to avoid this limitation, since stimulated photon fluxes are increased by the presence of the seed beam.Comment: 9 pages, 1 figur

BridA

BridA is a group of four Slovenian artists who formed a working collaborative while working on their respective graduate degrees. Their work spans between the technological and traditional as well as the scientific and artistic. Through their work they explore the possibilities of the information of science as expressible visual content in the art. Their methods cross continually from the digital to the analog. As a collective they work not only as artists but entrepreneurs within the context of the newly forming creative economy of Slovenia

The possibility of absolute calibration of analog detectors by using parametric down-conversion: a systematical study

Accurate calibration of photodetectors both in analog and in photon-counting regime is fundamental for various scientific applications, which range from "traditional" quantum optics to the studies on foundations of quantum mechanics, quantum cryptography, quantum computation, etc. In this paper we systematically study the possibility of the absolute calibration of analog photo-detectors based on the properties of parametric amplifiers. Our results show that such a method can be effectively developed with interesting possible metrological applications

Towards joint reconstruction of noise and losses in quantum channels

The calibration of a quantum channel, i.e. the determination of the transmission losses affecting it, is definitely one of the principal objectives in both the quantum communication and quantum metrology frameworks. Another task of the utmost relevance is the identification, e.g. by extracting its photon number distribution, of the noise potentially present in the channel. Here we present a protocol, based on the response of a photon-number-resolving detector at different quantum efficiencies, able to accomplish both of these tasks at once, providing with a single measurement an estimate of the transmission losses as well as the photon statistics of the noise present in the exploited quantum channel. We show and discuss the experimental results obtained in the practical implementation of such protocol, with different kinds and levels of noise.Comment: 6 pages, 4 figure

Quantum measurements in weak coupling regime: From Sequential weak values to protective measurements

8noQuantum measurements in weak coupling regime represent a new interesting paradigm with significant applications both conceptual and practical. Here we present several experimental achievements exploiting weak values, and the first realization of protective measurements.partially_openopenPiacentini F.; Avella A.; Rebufello E.; Virzi` S.; Gramegna M.; Brida G.; Degiovanni I.; Genovese M.Piacentini, F.; Avella, A.; Rebufello, E.; Virzi`, S.; Gramegna, M.; Brida, G.; Degiovanni, I.; Genovese, M

Recent experiments performed at "Carlo Novero" lab at INRIM on Quantum Information and Foundations of Quantum Mechanics

In this paper we present some recent work performed at "Carlo Novero" lab on Quantum Information and Foundations of Quantum Mechanics.Comment: Contribution to III international workshop "Recent advances in Foundations of Quantum Mechanics and Quantum Information. In memory of Carlo Novero

Photon number correlation for quantum enhanced imaging and sensing

In this review we present the potentialities and the achievements of the use of non-classical photon number correlations in twin beams (TWB) states for many applications, ranging from imaging to metrology. Photon number correlations in the quantum regime are easy to be produced and are rather robust against unavoidable experimental losses, and noise in some cases, if compared to the entanglement, where loosing one photon can completely compromise the state and its exploitable advantage. Here, we will focus on quantum enhanced protocols in which only phase-insensitive intensity measurements (photon number counting) are performed, which allow probing transmission/absorption properties of a system, leading for example to innovative target detection schemes in a strong background. In this framework, one of the advantages is that the sources experimentally available emit a wide number of pairwise correlated modes, which can be intercepted and exploited separately, for example by many pixels of a camera, providing a parallelism, essential in several applications, like wide field sub-shot-noise imaging and quantum enhanced ghost imaging. Finally, non-classical correlation enables new possibilities in quantum radiometry, e.g. the possibility of absolute calibration of a spatial resolving detector from the on-off- single photon regime to the linear regime, in the same setup

Quantum and classical characterization of single/few photon detectors

This paper's purpose is to review the results recently obtained in the Quantum Optics labs of the National Institute of Metrological Research (INRIM) in the field of single- and few-photon detectors calibration, from both the classical and quantum viewpoint. In the first part of the paper is presented the calibration of a single-photon detector with absolute methods, while in the second part we focus on photon-number-resolving detectors, discussing both the classical and quantum characterization of such devices.Comment: Quantum Matter in pres