Internship : Ultra high performant time transfer over optical fiber links


The Reference Laboratory for Time & Space (LNE-SYRTE) of the Paris Observatory is the national laboratory of time-frequency metrology. Time and frequency references have improved considerably in the last two decades, so that the usual GPS methods of comparison and dissemination are no longer sufficient for the performance of these new clocks.
That is why LNE-SYRTE develops, in close collaboration with the Laboratory of Physics of Lasers Paris 13 University (Sorbonne Paris Cité) and the telecommunication network for education and research RENATER, reference transfer technologies of time and frequency by optical fiber.
If the transfer of frequency is already well mastered and partly transferred to industrial partners, the transfer of time to very high performance, better than the ps, is a research still exploratory. In this sense, we develop original optical methods in order to achieve extreme precision in time. A demonstration of principle was carried out on a dedicated link connecting the two laboratories, the LNE-SYRTE and the LPL, with a resolution in time between 100 and 400 femtoseconds.


Summary of internship postition

The aim of the internship is to contribute to the improvement of the optical fiber time transfer experiments on the dedicated link linking the two laboratories, the LNE-SYRTE and the LPL. The aim is to study the sensitivity of the device to different experimental parameters such as temperature, optical levels and electronic levels of the signals, and to participate in the improvement of the results by realizing an optimized detection chain and signals conditioning.
In particular, specially designed digital modulators / demodulators are under study in the laboratory, with which we can vary many parameters, and which will be tested in the experiments during the internship. Gain and filtering at transmission, optimization of the signal to noise ratio will be studied.

A set of very high performance instruments equip the experiment, and will be used and compared in particular to determine the systematic bias affecting the time transfer.


Mentoring & Team

The trainee will be integrated into a project team composed of 2 senior research engineers, a researcher, a post-doctoral student, a doctoral student. Part of the work will be done in collaboration with a university professor and a research engineer at LPL. He or she will be supervised daily by a research engineer.

Responsable : Paul-Eric Pottie

LNE- SYRTE , Unité de recherche du CNRS UMR 8630

61, avenue de l’Observatoire 75014 Paris – France

tél 33 (0)1 40 51 22 22  fax 33 (0)1 43 25 55 42

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