Laboratoires scientifiques

Time and Frequency Laboratory of Besançon (LTFB)

The Time/Frequency laboratory of Besançon (LTFB) gathers means and competencies of two labora­tories of the University of Franche-Comté, UTINAM and FEMTO-ST; created in 2008, it is also the heir of the Time/ Frequency laboratory of the old Besançon Observa­tory (currently the Theta Universe’s Science Observatory).

It currently employs 80 people including 20 resear­chers/ teacher researchers, 20 PhD students and 40 technicians, engineers and administrative employees.



The LTFB ensures R&D activities through its two laboratories in different fields of Time/Frequency:

- Cryogenic oscillators
- Optical clocks
- Micro atomic clock
- Time and frequency transfer means
- Time and frequency transfer by optical fiber
- Theoretical studies, modelling/ characterization of oscillator stability


Time/Frequency metrology

The LTFB fulfill several missions: elaboration, maintenance and diffusion of national and international time/ frequency references. It is done in a close collaboration with the SYRTE which ensures at a national level, the connection with the International Committee of Weights and Measures. In this case, the LTFB is associated by contract with the LNE as “designated institute” as given by the international metrology authorities (BIPM, EURAMET) to implement the national CMC (Calibration and Measurement Capabilities) for some of the metrology scales (frequency, time interval, phase noise).

These commitments require from the metrological mission to be accomplished with an ISO/ CEI 17025:2005 accreditation. The service also has to be ensured with the support of a self-financed quality engineer. This association with the LNE guarantees an international recognition for all metrological missions led by the LTFB. The metrological service works thanks to a team of ten people from both laboratories.



The LTFB is based on two sites (the historical Observatory and the ENS2M site, an engineering school where the TF laboratory of FEMTO-ST is) a few hundred meters away.

Both sites are connected by optical fiber cables dedicated to it. They allow the sites to gather heavy equipment (hydrogen masers, Cesium standards, cryogenic oscillators).


2020 perspectives

The LTFB has invested in 2011-2012 in three PIA (LabeX FIRST-TF, Equipex OscIMP, Equipex REFIMEVE) that have been successful. This exceptional success is a recognition of the excellence of work done by the time/ frequency community in Besançon within the LTFB.

Among all the proposed projects thanks to the success and increasing strength of the OscIMP platform, the SCPTime® project plans on building and making available a highly stable time reference that will be a replica of the national reference provided by the Paris Observatory UTC(OP).

The operational imperatives of such an achievement (its implications regarding the underlying technical infrastructure and the increase of the accreditation perimeter for the inclusion of these equipment and function) are the challenge to be taken for the department and the LTFB on the 2015-2020 period of time.

The LTFB mainly takes part in the definition and qualification of methods and time transfer protocols (common view GNSS, NTP, PTP, PTP White Rabbit).

Register and be informed of the dates and topics of our upcoming on-line collaborative seminars