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Laser Physics Laboratory is affiliated both to CNRS and to University Paris 13. We study the interactions between light and matter.

Our experiments range from the most fundamental aspects of basic science to applied research: quantum physics, atomic and molecular physics, optical devices, biomedical imaging...

The lab is structured into eight experimental research teams, four shops and an administrative department. It is composed of about seventy-five people (10 CNRS full-time researchers, 30 university teaching staff members, a technical staff of 15 people, about 20 PhD students and post-docs), plus several short-term trainees and foreign visitors.

Olivier Gorceix,
Director of laboratory

Measuring the Boltzmann constant requires care …

Image PRADetermining spectroscopically line parameters of atomic or molecular resonances such as the width or the central frequency calls for some prudence. Well-known from the spectroscopy community, the rule of thumb formulated by Townes and Schawlow states that “The necessary ratio of bandwidth to sweep rate for good portrayal of a line cannot be specified uniquely, but is often of the order of 20” [1]. To go beyond this qualitative advice, we thoroughly modelled the influence of the detection chain with which a spectroscopic signal is recorded and precisely determined the lineshape deformation associated to absorption spectroscopy. Our study predicts artificial frequency shifts, extra broadenings and line asymmetries. This work was conducted in collaboration with F. Rohart (Laboratoire de Physique des Lasers, Atomes et Molécules, Lille) et L. Gianfrani’s group (Molecules and Precision Measurement Laboratory, Naples). It was motivated by efforts carried out in both Naples and Villetaneuse to measure the Boltzmann constant using laser spectroscopy. Indeed, given the targeted part per million uncertainty, determining a linear absorption spectrum Doppler broadening at the same level of accuracy is indispensable.

This work just appeared in Physical Review A and was selected by the editors of Physical Review A to be an Editors' Suggestion.

[1] Townes CH, Schawlow AL. Microwave Spectroscopy. McGraw-Hill, New York, 1955.


Can we create a mirage?At LPL, throughout the year we conduct many events dedicated to the popularization of science. Although this often happens behind the scenes, we occasionally make it into the limelight! Check us out on the TV show "On n'est pas que des Cobayes" broadcast during prime-time on France 5, Friday November the 14th.

TV show video: here.Explication...

Find out about our other experiments (lasers, color mixing,…) at the Atouts Sciences.

See also other news below ...

Science news of the laboratory
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General news of laboratory
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The awards and honors members of the laboratory
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