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Hong-Ou-Mandel (HOM) characterization of a Xenon filled hollow core fiber

Spécialité de Master « Optique, Matière, Paris »
             Stage de recherche 

Responsable du stage / internship supervisor:
Nom / name: DELAYE Prénom/ first name : Philippe
Tél : 01 64 53 34 60
Courriel / mail: Philippe.delaye@institutoptique.fr
Nom du Laboratoire / laboratory name: Laboratoire Charles Fabry (LCF)
Code d’identification : UMR 8501 Organisme : CNRS / IOGS
Site Internet / web site: www.institutoptique.fr
Adresse / address: 2 Avenue Augustin Fresnel, 91127 Palaiseau Cedex
Lieu du stage / internship place: Palaiseau

Entangled photon pair sources are a basic device of quantum communications systems. One common way to realize these sources is to use nonlinear mechanisms (spontaneous parametric down conversion and spontaneous four wave mixing) in waveguides. In such mechanisms one or two pump photons interact with the nonlinear media to create a pair of signal and idler photons that are correlated and even entangled. Generation of pairs of single photons directly in the core of an optical fiber, has several advantages: the low propagation losses and the confinement of light in the small dimension fiber core allow to reach high nonlinearity and thus high generation efficiency, the emitted photons can be efficiently coupled without losses to the optical communication network and the spectral properties of the emitted photon can be controlled by the dispersion properties of the fiber. Nevertheless, usual silica fibers suffer from the concomitant emission of a quasi-continuum of uncorrelated Raman photons that degrades the quantum quality of the emitted photon pairs.

One solution, we explore for now ten years in the NonLinear Photonics Group, consists in replacing the silica core by another media presenting spectrally thin Raman line that can be easily filtered, or even a media in which Raman vibrations are inexistent such as in Noble gases. This liquid or gaseous media fills an hollow core photonic crystal fiber to assure light guidance around the low index core.

Recently, in the frame of a collaboration with Telecom Paris and XLIM in Limoges, we have realized the first demonstration of a Raman free emission of pairs of photons in a Tubular Fiber filled with Xenon [1]. The proposed internship is in the continuity of this work. Using the experimental set-ups already developed in the group used for nanofibers and that will be adapted to the hollow core fiber, the student will operate a new xenon filled fiber optimized to operate with the Ti:Sapphire Laser we have in the group. This laser allows to have a tunable pump beam with different pulse duration in the femtosecond and picosecond regime, but also in the CW regime. A recently implemented Stimulated Emission Tomography set-up will also be used to characterize the pair emission before characterization of photon pairs emitted in the spontaneous regime using single photon detectors and coincidence counters. The performance of the fiber will be compared to theoretical models developed in the group. More specifically the aim of the fellowship will be to characterize the indistinguishability properties of the emitted pairs, and in particular to implement on our characterization set-up a Hong-Ou-Mandel (HOM) experiments to characterize the pairs of photons emitted by our source.

This fellowship will allow the student to become familiar to nonlinear and quantum optics experimental setups and will open the way to PhD work on new quantum information processing devices such as frequency converters for single photons.
[1] M. Cordier, et al. “Active engineering of four-wave mixing spectral correlations in multiband hollow-core fibers”, Opt. Exp 27, 9803 (2019). and M. Cordier, et al. “Raman-free fibered photon-pair generation”, Scientific Report 10, 1650 (2020).

 

Durée du stage:4 mois minimum, à partir de début mars 2021                                                                                      Ce stage pourra-t-il se prolonger en thèse ? Possibility of a PhD ? : Oui

Si oui, financement de thèse envisagé/ financial support for the PhD: EDOM, DGA, …