Defense of Thesis “Condensat de Bose-Einstein par refroidissement évaporatif dans un piège dipolaire pour la métrologie par interférométrie atomique”
The Defense will take place of UPMC – 4 Place Jussieu – 75005 Paris.
This research work fulfilled as part of my PhD project involved to design, build and characterise a new experimental setup based on an atom source by evaporative cooling in an optical dipole trap. It goes after the improvement of the uncertainty on the measurement of the ratio h/m between Planck’s constant and the rubidium atom mass, reducing the Gouy phase and wavefront curvature.
In a first step we have studied several optical configurations to optimise the dipole trap loading: the 50 W beam at 1070 nm is shaped in a double 93 μm waist reservoir and one crossed 20 μm waist dimple. After having optimised and caracterised the evaporative process, we obtained one Bose-Einstein condensate.
Furthermore, for Raman interferometry, we set up a new laser system at 1560 nm based on frequency doubling. We developed a double cervo loop: on the one hand, it allows to phase lock the two laser sources, and on the other hand to correct phase noise accumulated in fibered amplifiers.
Today, our new experimental setup is ready to perform atom interferometry on a Bose-Einstein condensate.