Partagez sur
STAGE Offre de stage: Optical phase locked loop for time and frequency metrology
Date de mise à jour de l’offre
Laboratoire SYRTE Observatoire de Paris :
Alliant recherche de très haut niveau et services scientifiques, le SYRTE se place aujourd’hui au premier rang international dans des champs disciplinaires variés : métrologie du temps et des fréquences, systèmes de référence célestes, rotation de la Terre, histoire de l’astronomie.
La pluridisciplinarité du SYRTE se retrouve aussi dans ses compétences transverses - théorie, instrumentation, traitement et analyse de données - et dans la diversité de ses objectifs qui vont de la physique fondamentale jusqu’au transfert industriel.
Le SYRTE a des partenariats avec plusieurs organismes publics, dont notamment le CNES, la DGA, l’ESA, le Bureau International des Poids et Mesures (BIPM), et de nombreux industriels. Il est membre fondateur du Laboratoire d’Excellence du Programme Investissements d’Avenir FIRST-TF.
Parallèlement à ses activités de recherche, le SYRTE assure des services nationaux et internationaux. Il compte en son sein le LNE-SYRTE.
Description de la mission
The future of time and frequency metrology lies in the optical domain : the second, the unit of time
will soon be defined via an optical transition in atoms ; optical clocks around the world have reported
unprecedented performance in both stability and accuracy ; and optical fiber networks provide
means of comparing distant clocks and disseminating frequency and time. In the heart of such
developments, an essential tool is the ultra-stable lasers.
Standard ultra-stable lasers nowadays derive their frequency stability from a Fabry-Perot cavity,
which has hit its fundamental stability limit since the early 2000s. Due to thermodynamic noise in
the cavity, the fractional frequency stability of these lasers are at a few 10-16 at 1 s average time.
Among the various paths taken in the search for improvement, a promising candidate is laser
spectroscopy with rare earth doped ions at cryogenic temperatures. With an optimal choice of the
crystalline matrix and dopant ion, very narrow spectroscopic features can be realized using the socalled ‘Spectral Hole Burning’ technique. These holes are then used as a reference to stabilize the
frequency of lasers. Fundamental limit of such a system is currently unknown but expected to be
below 10-18 at 1 s. This internship will contribute to the Spectral Hole Burning experiment of SYRTE.
Project
Central to the SHB experiment is the ultra-low noise heterodyne detection using two phase-locked
lasers. The phase relation between these two continuous wave lasers is locked on a stable microwave signal using an optical phase locked loop (OPLL). The residual relative phase noise between the
lasers enters directly into the detection noise. For the ultimate performance of our detection
scheme, it is therefore crucial to optimize the OPLL.
Conventional solutions based on analog electronics exist since more than 30 years. They constitute
the standard phase lock schemes already present on our experiment. However, the advent of digital
electronics provides the attractive possibilities of agile frequency control and atomization. We have
therefore collaborated with the startup company Koheron for a digital OPLL based on commercial
FPGA (Red Pitaya). The intern will first test the functionalities of the digital OPLL in order to evaluate
its performance in terms of locking bandwidth and residual noise. The former could be potentially
limited by digitization. Optimization should be carried out for our specific system.
will soon be defined via an optical transition in atoms ; optical clocks around the world have reported
unprecedented performance in both stability and accuracy ; and optical fiber networks provide
means of comparing distant clocks and disseminating frequency and time. In the heart of such
developments, an essential tool is the ultra-stable lasers.
Standard ultra-stable lasers nowadays derive their frequency stability from a Fabry-Perot cavity,
which has hit its fundamental stability limit since the early 2000s. Due to thermodynamic noise in
the cavity, the fractional frequency stability of these lasers are at a few 10-16 at 1 s average time.
Among the various paths taken in the search for improvement, a promising candidate is laser
spectroscopy with rare earth doped ions at cryogenic temperatures. With an optimal choice of the
crystalline matrix and dopant ion, very narrow spectroscopic features can be realized using the socalled ‘Spectral Hole Burning’ technique. These holes are then used as a reference to stabilize the
frequency of lasers. Fundamental limit of such a system is currently unknown but expected to be
below 10-18 at 1 s. This internship will contribute to the Spectral Hole Burning experiment of SYRTE.
Project
Central to the SHB experiment is the ultra-low noise heterodyne detection using two phase-locked
lasers. The phase relation between these two continuous wave lasers is locked on a stable microwave signal using an optical phase locked loop (OPLL). The residual relative phase noise between the
lasers enters directly into the detection noise. For the ultimate performance of our detection
scheme, it is therefore crucial to optimize the OPLL.
Conventional solutions based on analog electronics exist since more than 30 years. They constitute
the standard phase lock schemes already present on our experiment. However, the advent of digital
electronics provides the attractive possibilities of agile frequency control and atomization. We have
therefore collaborated with the startup company Koheron for a digital OPLL based on commercial
FPGA (Red Pitaya). The intern will first test the functionalities of the digital OPLL in order to evaluate
its performance in terms of locking bandwidth and residual noise. The former could be potentially
limited by digitization. Optimization should be carried out for our specific system.
Profil recherché
We are looking for a serious candidate with professionalism. Technically, he/she should be familiar
with standard optics, laser, analog and digital electronics. Prior experience with FPGA programming
is appreciated but not necessary. Given the international context of the subject and the laboratory,
technical English is indispensable.
with standard optics, laser, analog and digital electronics. Prior experience with FPGA programming
is appreciated but not necessary. Given the international context of the subject and the laboratory,
technical English is indispensable.
Niveau de qualification requis
Bac + 4/5 et +
Les offres de stage ou de contrat sont définies par les recruteurs eux-mêmes.
En sa qualité d’hébergeur dans le cadre du dispositif des « 100 000 stages », la Région Île-de-France est soumise à un régime de responsabilité atténuée prévu aux articles 6.I.2 et suivants de la loi n°2204-575 du 21 juin 2004 sur la confiance dans l’économie numérique.
La Région Île-de-France ne saurait être tenue responsable du contenu des offres.
Néanmoins, si vous détectez une offre frauduleuse, abusive ou discriminatoire vous pouvez la signaler
en cliquant sur ce lien.
-
EmployeurLaboratoire SYRTE Observatoire de Paris
-
Secteur d’activité de la structureEnseignement - Formation - Recherche
-
Effectif de la structureDe 51 à 250 salariés
-
Site internet de la structurehttps://syrte.obspm.fr
-
Type de stage ou contratStage pour lycéens et étudiants en formation initiale
-
Date prévisionnelle de démarrage
-
Durée du stage ou contratPlus de 4 mois et jusqu'à 6 mois
-
Le stage est-il rémunéré ?Oui
-
Niveau de qualification requis
Bac + 4/5 et + -
Lieu du stage61 Avenue de l'Observatoire
75014 PARIS 14E ARRONDISSEMENT -
Accès et transportsRER B Denfert Rochereau