Implementing two-photon interference in the frequency domain with electro-optic phase modulators

Frequency-entangled photons can be readily produced using parametric down-conversion. We have recently shown how such entanglement could be manipulated and measured using electro-optic phase modulators and narrow-band frequency filters, thereby leading to two-photon interference patterns in the frequency domain. Here we introduce new theoretical and experimental developments showing that this method is potentially a competitive platform for the realization of quantum communication protocols in standard telecommunication fibres. We derive a simple theoretical expression for the coincidence probabilities and use it to optimize a Bell inequality. Furthermore, we establish an equivalence between the entangled- photon scheme and a classical interference scheme. Our measurements of two-photon interference in the frequency domain yield raw visibilities in excess of 99%. We use our high quality setup to experimentally validate the theoretical predictions, and in particular we report a violation of the CH74 inequality by more than 18 standard deviations.Comment: 19 pages, 3 figure

Manipulation de photons intriqués en fréquence

Les pères fondateurs de la mécanique quantique exploraient les implications de leur théorie avec des "expériences de pensée". Les améliorations continuelles en matière de manipulation de systèmes quantiques individuels ont ouvert la voie à des recherches théoriques et expérimentales. C'est la base de l'information quantique: quand un contenu informationnel est associé à des transformations et mesures sur des systèmes quantiques, cela offre un nouveau paradigme à la théorie de l'information. Une des promesses de l'information quantique est la réalisation d'un internet quantique: des liaisons quantiques permettraient de partager des états quantiques entre les noeuds du réseau. Le contexte de notre travail est l'optique quantique expérimentale dans des fibres optiques aux longueurs d'onde des télécommunications, avec comme perspective des applications en communication quantique. Nous démontrons une nouvelle méthode pour manipuler des photons intriqués en énergie-temps, en utilisant des composants fibrés et optoélectroniques standard. Les photons produits par paires par une source de conversion paramétrique sont envoyés dans des modulateurs de phase électro-optiques indépendants, qui agissent comme des diviseurs de faisceau en fréquence. Nous utilisons ensuite des filtres fréquentiels et des détecteurs de photons uniques pour discriminer les fréquences des photons. Nos résultats expérimentaux incluent l'obtention d'interférences à deux photons robustes, à haute visibilité et à haute dimension, qui permettent la violation d'inégalités de Bell. Cela montre qu'une telle "intrication en bins fréquentiels" est une plate-forme intéressante pour la communication Quantique.The founding fathers of quantum mechanics explored the implications of their theory with "gedanken experiments". Continuous improvement of the experimental manipulation of individual quantum systems has opened the way to exciting research, both on blackboards and in laboratories. lt is the basis for quantum information processing : when an information content is associated with transformations and measurements of quantum systems, it offers a new paradigm, full of potentialities, to information theory. One of the promises of quantum information is the realization of a quantum internet: quantum communication links would allow to share quantum states between the nodes of the network.Our work lies in the context of experimental quantum optics in optical fibers at telecommunication wavelengths, in view of quantum communication applications. We demonstrate a new method for manipulating photons entangled in their energy-time degree of freedom, by using standard fiber-optic and optoelectronic components. The photon pairs produced by a parametric down-conversion source are sent through independent electro­optic phase modulators, which act as high-dimensional frequency beam splitters. We then use frequency filters and single-photon detectors to discriminate the frequencies of the photons. Our experimental results include robust, high-visibility and high-dimensional two­photon interference patterns allowing Bell inequality violations. This shows that such a "frequency -bin entanglement" provides an interesting platform for quantum communication

Manipulation de photons intriqués en fréquence

The founding fathers of quantum mechanics explored the implications of their theory with "gedanken experiments". Continuous improvement of the experimental manipulation of individual quantum systems has opened the way to exciting research, both on blackboards and in laboratories. lt is the basis for quantum information processing : when an information content is associated with transformations and measurements of quantum systems, it offers a new paradigm, full of potentialities, to information theory. One of the promises of quantum information is the realization of a quantum internet: quantum communication links would allow to share quantum states between the nodes of the network.Our work lies in the context of experimental quantum optics in optical fibers at telecommunication wavelengths, in view of quantum communication applications. We demonstrate a new method for manipulating photons entangled in their energy-time degree of freedom, by using standard fiber-optic and optoelectronic components. The photon pairs produced by a parametric down-conversion source are sent through independent electro­optic phase modulators, which act as high-dimensional frequency beam splitters. We then use frequency filters and single-photon detectors to discriminate the frequencies of the photons. Our experimental results include robust, high-visibility and high-dimensional two­photon interference patterns allowing Bell inequality violations. This shows that such a "frequency -bin entanglement" provides an interesting platform for quantum communication.Les pères fondateurs de la mécanique quantique exploraient les implications de leur théorie avec des "expériences de pensée". Les améliorations continuelles en matière de manipulation de systèmes quantiques individuels ont ouvert la voie à des recherches théoriques et expérimentales. C'est la base de l'information quantique: quand un contenu informationnel est associé à des transformations et mesures sur des systèmes quantiques, cela offre un nouveau paradigme à la théorie de l'information. Une des promesses de l'information quantique est la réalisation d'un internet quantique: des liaisons quantiques permettraient de partager des états quantiques entre les noeuds du réseau. Le contexte de notre travail est l'optique quantique expérimentale dans des fibres optiques aux longueurs d'onde des télécommunications, avec comme perspective des applications en communication quantique. Nous démontrons une nouvelle méthode pour manipuler des photons intriqués en énergie-temps, en utilisant des composants fibrés et optoélectroniques standard. Les photons produits par paires par une source de conversion paramétrique sont envoyés dans des modulateurs de phase électro-optiques indépendants, qui agissent comme des diviseurs de faisceau en fréquence. Nous utilisons ensuite des filtres fréquentiels et des détecteurs de photons uniques pour discriminer les fréquences des photons. Nos résultats expérimentaux incluent l'obtention d'interférences à deux photons robustes, à haute visibilité et à haute dimension, qui permettent la violation d'inégalités de Bell. Cela montre qu'une telle "intrication en bins fréquentiels" est une plate-forme intéressante pour la communication Quantique

Bell Inequality Violation in Frequency Domain using 25 GHz Frequency Sideband Modulation Architecture

Poster ED_P3_THUinfo:eu-repo/semantics/publishe

Creating and manipulating entangled optical qubits in the frequency domain

International audienceRadio-frequency phase modulation of frequency-entangled photons leads to a two-photon interference pattern in the frequency domain. In recent experiments, the pattern was measured with narrow-band frequency filters which select photons belonging to a given frequency bin. Here we show how photons can be grouped into even and odd frequencies by using periodic frequency filters called interleavers. In our theoretical analysis we show how this reduces the high-dimensional photon state to an effective two-dimensional state. This is of interest for applications such as quantum cryptography or low-dimensional tests of quantum nonlocality. We then report an experimental realization of this proposal. The observed two-photon interference pattern and violation of the CHSH inequality—the simplest binary-outcome Bell inequality—are in good agreement with the theoretical predictions

Creation and manipulation of two-dimensional photonic frequency entanglement

info:eu-repo/semantics/publishe

Creating and manipulating entangled optical qubits in the frequency domain

info:eu-repo/semantics/publishe

Propagation and survival of frequency-bin entangled photons in metallic nanostructures

International audienceWe report on the design of two plasmonic nanos-tructures and the propagation of frequency-bin entangled photons through them. The experimental findings clearly show the robustness of frequency-bin entangle-ment, which survives after interactions with both a hybrid plasmo-photonic structure, and a nano-pillar array. These results confirm that quantum states can be encoded into the collective motion of a many-body electronic system without demolishing their quantum nature, and pave the way towards applications of plasmonic structures in quantum information

Propagation and survival of frequency-bin entangled photons in metallic nanostructures

We report on the design of two plasmonic nanostructures and the propagation of frequency-bin entangled photons through them. The experimental findings clearly show the robustness of frequency-bin entanglement, which survives after interactions with both a hybrid plasmo-photonic structure, and a nano-pillar array. These results confirm that quantum states can be encoded into the collective motion of a many-body electronic system without demolishing their quantum nature, and pave the way towards applications of plasmonic structures in quantum information

Manipulating Frequency Entanglement with Phase Modulators

info:eu-repo/semantics/publishe