The random laser is a new type of laser, whose feedback mechanism is provided by multiple scattering, in a random medium with gain. Our projet is to produce such a laser, with 85Rb cold atoms trapped in a magneto-optical trap, as gain and scattering medium. In this thesis, we present several process of gain in cold atoms, which we have studied...
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November 14, 2008 (v1)PublicationUploaded on: December 3, 2022
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December 5, 2005 (v1)Publication
We have observed self-sustained radial oscillations in a large magneto-optical trap (MOT), containing up to $10^{10}$ Rb$^{85}$ atoms. This instability is due to the competition between the confining force of the MOT and the repulsive interaction associated with multiple scattering of light inside the cold atomic cloud. A simple analytical...
Uploaded on: December 3, 2022 -
August 29, 2008 (v1)Journal article
We realize a laser with a cloud of cold rubidium atoms as gain medium, placed in a low-finesse cavity. Three different regimes of laser emission are observed corresponding respectively to Mollow, Raman and Four Wave Mixing mechanisms. We measure an output power of up to 300 µW and present the main properties of these different lasers in each regime.
Uploaded on: December 4, 2022 -
2006 (v1)Journal article
We have investigated degenerate four-wave mixing in a sample of cold rubidium atoms. A red-blue asymmetry is observed for high intensities of the pumping beams. This asymmetry is explained by the spatial bunching of the atoms in the nodes or antinodes of the strong standing wave of the pump beams. This explanation is confirmed by different...
Uploaded on: March 26, 2023 -
2010 (v1)Journal article
Atoms can scatter light and they can also amplify it by stimulated emission. From this simple starting point, we examine the possibility of realizing a random laser in a cloud of laser-cooled atoms. The answer is not obvious as both processes (elastic scattering and stimulated emission) seem to exclude one another: pumping atoms to make them...
Uploaded on: December 3, 2022