Fabien Théron will defend his PhD thesis , entitled “Development of a cold atom gravity gradiometer and a telecom doubled laser device for onboard applications”, which work was accomplished in ONERA . The defense will take place on Friday, Friday, 27 of November 2015 at 14:00 in Institut d’Optique Graduate School (Auditorium), Palaiseau.

Summary :

This thesis presents the development of the experimental setup allowing the measurement of two gravity gradient components and the gravity acceleration. These quantities are resulted from the measuring of rubidium cold atoms acceleration, in free fall in vacuum, by atom interferometry. For gradiometry, the differential measurement is realized between two atomic clouds spatially separated. For the measurement of vertical gradient, the use of mobile optical lattices allows to get two atom clouds from a single atomic source.

This work presents the setting up of the complete device, in particular with the built of the vaccum chamber, laser and micro-wave systems. Lasers are based on frequency-doubled telecom technology, which allows to obtain compact and robust systems, dedicated for onboard applications. The innovative laser architecture allows to combine atom interferometry and optical lattices, while minimizing the amount of components. The laser noise has been characterized, and limits the single shot gravimetric sensitivity to 10-9 g, the single shot differential sensitivity to 10-10 g, and the single shot gradiometric sensitivity to 38 E.

Indranil DUTTA will defend his PhD thesis , entitled “Stability Improvement of a Sagnac Cold Atom Interferometer: towards Continuous Operation”, which work was accomplished in SYRTE under the supervision of Arnaud Landragin. The defense will take place on Friday, 20 of November 2015 at 14:30 in Paris Observatory (Salle de l’IAP).

Summary on the thesis work

Valerian Thiel will defend his PhD thesis, , entitled “Modal analysis of an ultrafast frequency comb: from classical to quantum spectral correlations”, which work was accomplished in Laboratoire Kastler Brossel under the supervision of Nicolas Treps. It will take place on Monday the 19^th of October in the amphitheater Herpin, building Esclangon, at Université Pierre et Marie Curie. The defense will be in english.

As the other Labex of the French “Programme Investissements d’Avenir” (PIA) , FIRST-TF has been evaluated in 2015 by an international committee. The conclusions drawn from this evaluation are very positive: they point out the federative role of FIRST-TF for the T/F community and the efficiency of the supports to collaborative projects in Research, Training, Innovation, Outreach. The committee emphasized the need to find a solution in order to follow up FIRST-TF after 2019 which will be the end of the contract between CNRS (organisation in charge of the coordination FIRST-TF) and ANR.

Written by Jacques Vanier and Cipriana Tomescu, this book reviews conventional atomic frequency standards as described in the previous two volumes. It describes the development that has been done since the 1990s in improving conventional frequency standards. It covers the research and development done in the optical range to implement an optical frequency standard. It is designed for those groups and companies working in the areas of high-speed communications and data networks, navigation systems, satellites, GPS, timekeeping, and more.

 

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