24th of November 2017 (Paris) – PhD defense of Denis Savoie

Denis Savoie will defend his thesis on 24th November 2017 at 2 pm on the subject “Continuous and interleaved operation of a cold atom gyroscope and improvement of its stability”, realized at SYRTE laboratory under the direction of Arnaud Landragin and co-supervised by Remi Geiger.

The defense will take place in the main amphitheater of the Institut d’Astrophysique de Paris.

21st of November 2017 (Paris) – PhD defense of Romain Bouchand

Romain Bouchand will defend his thesis on 21st November 2017 at 4 pm on the subject “Optical frequency comb-based ultralow phase noise photonic microwave generation”, realized at SYRTE laboratory under the direction of Yann Lecoq.

The defense will take place in the main amphitheater of the Institut d’Astrophysique de Paris.

The defense will be in english.

10th of November 2017 (Paris) – PhD defense of Slawomir Bilicki

Slawomir Bilicki will defend his thesis on 10th November 2017 at 2 pm on the subject “Strontium optical lattice clocks: clock comparisons for timescales and fundamental physics applications”, realized at SYRTE laboratory under direction of Sébastien Bize and supervised by Jérôme Lodewyck.

The defense will take place in the main amphitheater of the Institut d’Astrophysique de Paris.

The defense will be in english.

26th of October 2017 (Paris) – PhD defense of Hélène FLEURBAEY

Hélène Fleurbay will defend her thesis on 26th october 2017 in the Durand amphitheater at UPMC (Paris) at 2 pm on the subject “Frequency metrology of the 1S-3S transition of hydrogen: contribution to the proton charge radius puzzle”. This work has been done in Laboratoire Kastler Brossel (LKB) under the supervision of François Nez.

The defense will be in english.

11th of October 2017 (Paris) – PhD defense of Maxime Favier

Maxime Favier will defend his thesis on 11th october 2017 at IAP (Paris) at 14:00 on the subject “Mercury optical lattice clock: from high-resolution spectroscopy to frequency ratio measurements”, realized at the SYRTE under the direction of Sébastien Bize and supervised by Sébastien Bize and Luigi De Sarlo.

The defense will take place in room “Salle des séminaires” of the “Institut d’Astrophysique de Paris” (IAP) located 98 bis boulevard Arago, 75014 Paris, in front of a jury composed of Martina Knoop, Leonardo Fallani, Thomas Udem, Philippe Grangier and Jean-Michel Raimond.

The defense will be in english.

⇒ More information

ITSNT 2017, symposium on Navigation and Timing

ITSNT 2017, symposium on Navigation and Timing : 14-17 Nov 2017 at ENAC (Toulouse, France).

The International Technical Symposium on Navigation and Timing also known as the ITSNT, is an annual event organized by CNES and ENAC for professionals and researchers working with or interested in navigation and timing technologies and their use. This event focuses specifically on technical topics that are addressed by experts from all around the world that share their ideas, expertise and views. The audience can easily engage in discussion with these experts during the question sessions and  round tables. The ITSNT also provides a great environment for networking and visiting our sponsors’ exhibition stands.

Key elements:

  • International event
  • A high quality and recognized scientific committee
  • Technical presentations on hot topics related to navigation and timing
  • Internationally recognized guest speakers
  • Selective call for abstract
  • Round tables
  • Exhibition area
  • Networking
  • Tutorials

http://www.itsnt.fr/en/home/4

21st of September 2017 (Paris) – PhD defense of Charles PHILIPPE

Charles PHILIPPE will defense his PhD on the 21st of September, 2017 at IAP (Paris) on the topic “Source laser à 1.5 µm stabilisée en fréquence sur l’iode moléculaire”. This work took place at SYRTE laboratory under the supervision of Ouali ACEF and Peter WOLF.

 

Abstract:

This thesis reports on the development of a frequency stabilization of a 1.54 µm laser diode on iodine hyperfine line at 514 nm, after a frequency tripling process.

An important part of this work is dedicated to the development of the frequency tripling process of a 1.54 µm laser diode, using two periodically polled wave guided Lithium Niobate nonlinear crystals.  A nonlinear conversion efficiency P3w/Pw > 36 % is obtained. This result is the best efficiency ever demonstrated for a CW frequency tripling process. 300 mW of harmonic power is generated at 514 nm from a fundamental optical power of 800 mW at 1.54 µm. The optical setup is fully fibered. The total power consumption needed to fulfill this frequency tripling process is 20 W only. According a specific operation mode, this laser setup emits simultaneously three frequency-stabilized and intense radiations at 1.54 µm, 771 nm and 514 nm.

Following this development, a very compact laser spectroscopy setup is buildup, based on a short sealed quartz cell, which contains the molecular iodine vapor. An optical power lower than 10 mW in the green is sufficient to fulfill the iodine vapor interrogation, and to detect the hyperfine saturation transitions, whose have a high factor around 514 nm (Q > 2×109).

A frequency stability at the level of 4.5 x 10-14 t-1/2 with a minimum value of 6 x 10-15 from 50 s to 100 s is demonstrated in this study. This frequency stability is the best result ever conferred to a laser diode at 1.54 µm, using in simple way a Doppler-free iodine spectroscopy technique.

This work has allowed to identify the major key components, in order to develop in near future, a fully fibered and compact stabilized laser prototype occupying a total optical volume < 10 liters.

This development could answer to numerous needs of space mission’s projects requiring ultra-stable frequency optical link, inter-satellite or ground to space, for the space geodesy (GRICE), the earth gravitational field measurement (GRACE-FO, NGGM), the gravitational waves detection (LISA) , etc …

 

Keywords: Metrology, frequency stabilization, ultra-stable lasers, Iodine optical clock, nonlinear optic, tripling frequency process, Telecom Laser, 1.5 µm, 514 nm, space.