Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:quant-ph/0612198 · Physical Review A

Sub-shot-noise photon-number correlation in a mesoscopic twin beam of light

Maria Bondani, Alessia Allevi, Guido Zambra, Matteo G. A. Paris, Alessandra Andreoni

Published Jul 27, 2007• 154 citations
arXivHTMLPDF

Abstract

We demonstrate sub-shot-noise photon-number correlations in a (temporal) multimode mesoscopic ($\ensuremath{\sim}{10}^{3}$ detected photons) twin beam produced by picosecond-pulsed spontaneous nondegenerate parametric down-conversion. We have separately detected the signal and idler distributions of photons collected in twin coherence areas and found that the variance of the photon-count difference goes below the shot-noise limit by $3.25\phantom{\rule{0.3em}{0ex}}\mathrm{dB}$. The number of temporal modes contained in the twin beam, as well as the size of the twin coherence areas, depends on the pump intensity. Our scheme is based on spontaneous down-conversion and thus does not suffer from limitations due to the finite gain of the parametric process. Twin beams are also used to demonstrate the conditional preparation of a nonclassical (sub-Poissonian) state.

DOI
10.1103/physreva.76.013833

Related papers

Nonclassical mesoscopic twin-beam of light

Maria Bondani, Alessia Allevi, Guido Zambra +5 more

We demonstrate, by direct measurement of the number of photons in signal and idler, that the twin-beam of light produced by ps-pulsed spontaneous parametric downconversion is endowed with sub-shot-noise photon-number correlations in a mesoscopic intensity regime (more than 1000 detected photons). The noise reduction, calculated from the variance of the difference in the numbers of detected-photons, resulted to be 3.25 dB below the shot-noise level. From experimental data we can recover joint photon-number distribution and a negative-valued joint signal-idler quasi-distributions of integrated intensities, which demonstrates the nonclassical character of the generated field.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 11, 2007•0 citations

Experimental joint signal-idler quasidistributions and photon-number statistics for mesoscopic twin beams

Jan Peřina, J. Křepelka, Jan Peřina +3 more

Joint signal-idler photoelectron distributions of twin beams containing several tens of photons per mode have been measured recently. Exploiting a microscopic quantum theory for joint quasidistributions in parametric down-conversion developed earlier we characterize properties of twin beams in terms of quasidistributions using experimental data. Negative values as well as oscillating behavior in the quantum region are characteristic for the subsequently determined joint signal-idler quasidistributions of integrated intensities. Also the conditional and difference photon-number distributions are shown to be sub-Poissonian and sub-shot-noise, respectively.

arXiv:0708.2216•Physical Review A•Oct 9, 2007•25 citations

Photocount measurements as a tool for investigation of non-classical properties of twin beams

Jan Peřina, Jan Peřina, Ondřej Haderka +6 more

Joint signal-idler photoelectron distributions of twin beams have been measured recently in two distinct regimes: either the mean number of photon pairs per one pump pulse is lower that the number of independent modes or vice versa. Exploiting a microscopic quantum theory for joint quasi-distributions in parametric down-conversion based on the model of superposition of signal and noise we characterize properties of twin beams in terms of quasidistributions using experimental data. In parallel to the microscopic model, joint signal-idler photon-number distribution is reconstructed using the method of maximum likelihood. Negative values as well as oscillating behavior in quantum region are characteristic for the joint signal-idler quasi-distributions of integrated intensities. The larger the mean number of photon pairs per mode the weaker the quantum features are. However, they survive even in the mesoscopic regime, i.e. when tens of photon pairs per mode are present on average. Also the conditional and difference photon-number distributions are shown to be sub-Poissonian and sub-shot-noise, respectively. Violation of classical inequalities for photon-number distributions is discussed.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Nov 20, 2008•1 citation

Generalized sub-Poissonian states of two-beam fields

Jan Peřina, Kishore Thapliyal, Ondřej Haderka +2 more

Two-beam states obtained by partial photon-number-resolving detection in one beam of a multi-mode twin beam are experimentally investigated using an intensified CCD camera. In these states, sub-Poissonian photon-number distributions in one beam are accompanied by sub-shot-noise fluctuations in the photon-number difference of both beams. Multi-mode character of the twin beam implying the beam nearly Poissonian statistics is critical for reaching sub-Poissonian photon-number distributions, which contrasts with the use of a two-mode squeezed vacuum state. Relative intensities of both nonclassical effects as they depend on the generation conditions are investigated both theoretically and experimentally using photon-number distributions of these fields. Fano factor, noise-reduction parameter, local and global nonclassicality depths, degree of photon-number coherence, mutual entropy as a non-Gaussianity quantifier, and negative quasi-distributions of integrated intensities are used to characterize these fields. Spatial photon-pair correlations as means for improving the field properties are employed. These states are appealing for quantum metrology and imaging including the virtual-state entangled-photon spectroscopy.

Optics Express•Dec 12, 2023•5 citations

Measuring nonclassical correlation of sub-picosecond pulsed mesoscopic twin-beam states

Alex Pozzoli, Marco Lamperti, Matteo Clerici +2 more

The robustness of nonclassical correlations exhibited by mesoscopic twin-beam states of light makes them useful for applications in the context of quantum technologies, such as for underwater quantum communication. To this aim, it is crucial to optimize the production of such quantum states of light, and study their level of nonclassicality in terms of different nonclassicality criteria. In this work, we realize an efficient source of well-populated twin-beam states in the red spectral region by pumping parametric down conversion with a natively sub-picosecond laser system. The nonclassical character of such states is investigated in terms of both the noise reduction factor and high-order correlation functions. The obtained results encourage the exploitation of this source in further optical schemes for practical applications.

International Journal of Quantum Information•Dec 11, 2025•0 citations

Optimal sub-Poissonian light generation from twin beams by photon-number resolving detectors

Marco Lamperti, Alessia Allevi, Maria Bondani +4 more

We generate nonclassical conditional states by exploiting the quantum correlations of multimode twin-beam states endowed with a sizeable number of photons. A strong relation between the sub-shot-noise correlations exhibited by twin beams and the sub-Poissonian character of the conditional states is experimentally revealed, determining the optimal conditions for sub-Poissonian light generation.

arXiv:1305.5350•Journal of the Optical Society of America B•Dec 2, 2013•39 citations
We demonstrate sub-shot-noise photon-number correlations in a (temporal) multimode mesoscopic (\ensuremath∼103\ensuremath{\sim}{10}^{3}\ensuremath∼103 detected photons) twin beam produced by picosecond-pulsed spontaneous nondegenerate parametric down-conversion. We have separately detected the signal and idler distributions of photons collected in twin coherence areas and found that the variance of the photon-count difference goes below the shot-noise limit by 3.25dB3.25\phantom{\rule{0.3em}{0ex}}\mathrm{dB}3.25dB. The number of temporal modes contained in the twin beam, as well as the size of the twin coherence areas, depends on the pump intensity. Our scheme is based on spontaneous down-conversion and thus does not suffer from limitations due to the finite gain of the parametric process. Twin beams are also used to demonstrate the conditional preparation of a nonclassical (sub-Poissonian) state.
We demonstrate, by direct measurement of the number of photons in signal and idler, that the twin-beam of light produced by ps-pulsed spontaneous parametric downconversion is endowed with sub-shot-noise photon-number correlations in a mesoscopic intensity regime (more than 1000 detected photons). The noise reduction, calculated from the variance of the difference in the numbers of detected-photons, resulted to be 3.25 dB below the shot-noise level. From experimental data we can recover joint photon-number distribution and a negative-valued joint signal-idler quasi-distributions of integrated intensities, which demonstrates the nonclassical character of the generated field.
Joint signal-idler photoelectron distributions of twin beams containing several tens of photons per mode have been measured recently. Exploiting a microscopic quantum theory for joint quasidistributions in parametric down-conversion developed earlier we characterize properties of twin beams in terms of quasidistributions using experimental data. Negative values as well as oscillating behavior in the quantum region are characteristic for the subsequently determined joint signal-idler quasidistributions of integrated intensities. Also the conditional and difference photon-number distributions are shown to be sub-Poissonian and sub-shot-noise, respectively.
Joint signal-idler photoelectron distributions of twin beams have been measured recently in two distinct regimes: either the mean number of photon pairs per one pump pulse is lower that the number of independent modes or vice versa. Exploiting a microscopic quantum theory for joint quasi-distributions in parametric down-conversion based on the model of superposition of signal and noise we characterize properties of twin beams in terms of quasidistributions using experimental data. In parallel to the microscopic model, joint signal-idler photon-number distribution is reconstructed using the method of maximum likelihood. Negative values as well as oscillating behavior in quantum region are characteristic for the joint signal-idler quasi-distributions of integrated intensities. The larger the mean number of photon pairs per mode the weaker the quantum features are. However, they survive even in the mesoscopic regime, i.e. when tens of photon pairs per mode are present on average. Also the conditional and difference photon-number distributions are shown to be sub-Poissonian and sub-shot-noise, respectively. Violation of classical inequalities for photon-number distributions is discussed.
Two-beam states obtained by partial photon-number-resolving detection in one beam of a multi-mode twin beam are experimentally investigated using an intensified CCD camera. In these states, sub-Poissonian photon-number distributions in one beam are accompanied by sub-shot-noise fluctuations in the photon-number difference of both beams. Multi-mode character of the twin beam implying the beam nearly Poissonian statistics is critical for reaching sub-Poissonian photon-number distributions, which contrasts with the use of a two-mode squeezed vacuum state. Relative intensities of both nonclassical effects as they depend on the generation conditions are investigated both theoretically and experimentally using photon-number distributions of these fields. Fano factor, noise-reduction parameter, local and global nonclassicality depths, degree of photon-number coherence, mutual entropy as a non-Gaussianity quantifier, and negative quasi-distributions of integrated intensities are used to characterize these fields. Spatial photon-pair correlations as means for improving the field properties are employed. These states are appealing for quantum metrology and imaging including the virtual-state entangled-photon spectroscopy.
The robustness of nonclassical correlations exhibited by mesoscopic twin-beam states of light makes them useful for applications in the context of quantum technologies, such as for underwater quantum communication. To this aim, it is crucial to optimize the production of such quantum states of light, and study their level of nonclassicality in terms of different nonclassicality criteria. In this work, we realize an efficient source of well-populated twin-beam states in the red spectral region by pumping parametric down conversion with a natively sub-picosecond laser system. The nonclassical character of such states is investigated in terms of both the noise reduction factor and high-order correlation functions. The obtained results encourage the exploitation of this source in further optical schemes for practical applications.