18 months Postdoctoral position available in the OHMS team at FEMTO-ST (Besançon, France) to study a new generation of ultra-stable optical Fabry-Perot cavity.

The aim of this work is to study a new generation of ultra-stable optical Fabry-Perot cavity. Such a cavity, made from single crystal silicon maintained below 1 K, will be used as the frequency reference for an ultra-stable laser. It will pave the way for the next generation of ultra-stable lasers with fractional frequency stability lower than 10-17.
As a first step, the Fabry-Perot cavity will be placed and cooled down in a dilution cryostat. A laser source will be frequency-locked to the cavity in order to access its optical properties. Refine measurement of those properties is the second step. The last step will focus on performances characterization to demonstrate the potential of this ultra-low temperature reference.

More information here.

2021 FIRST-TF General Assembly – Paris: Registrations are now open!

The FIRST-TF General Assembly will take place on October 21 and 22, 2021 in Paris at the Paris Observatory site.

Participation at the General Assembly is free but registration is mandatory. Please, register before September 30, 2021: Register for the FIRST-TF 2021 GA here

Practical information as well as the GA program can be viewed (very soon) here: https://first-tf.com/the-network/presentation/general-assemblies/



Gravitime Pendulum is a simple maintained pendulum in order to realize a travelling educational experiment,dedicated to scientific events for the general public, for high schools and museum institutions all over the world.Its essential aim being to sensitize the public to the metrological procedure through the operation of identificationof the acceleration of gravity by the measure of different frequencies.
A “general public” conference as part of the “Nuit des Temps” event was recorded. Please find it on the SFP YouTube channel: Gravitime Pendulum


PhD defense by Lucas Groult – July 7st 2021 at 2PM

Lucas Groult will defend his thesis on July 7th 2021, entitled: “Conception d’un piège de Paul microfabriqué pour le développement d’une horloge optique compacte, à ion piégé Yb+”, prepared at the University of Bourgogne Franche-Comté, in collaboration with FEMTO-ST and under the supervision of Yann Kersalé. The defense will be  in the amphithéâtre Jules Haag – ENSMM – 26, Rue de l’Epitaphe – Besançon.

Rodolphe Boudot (FEMTO-ST) received the 2020 EFTF Young Scientist Award

The EFTF Young Scientist Award 2020 goes to Dr. Rodolphe Boudot ,”for his outstanding contributions to the development of high-performance compact and miniature CPT atomic clocks.”
The EFTF Young Scientist Award is conferred in recognition of a personal contribution that demonstrated a high degree of initiative and creativity and led to already established or easily foreseeable outstanding advances in the field of time and frequency metrology. The award honours a person under the age of 40 at the date of the opening session of the EFTF conference.