Theoretical and experimental developments for a continuous superradiant laser

This work presents the groundwork for an ultrastable optical frequency reference based on the quantum phenomenon of superradiance, with both theoretical modeling and experimental implementation. A superradiant laser results from the collective emission of an atomic ensemble in an optical cavity, and it can show frequency stability largely independent of cavity fluctuations.

The system studied in this thesis is composed of cold ytterbium atoms coupled to a Fabry-Perot cavity operating in the bad-cavity regime, with a special focus on the criteria required to reach a continuous superradiant emission. The experimental work follows the scheme developed at the FEMTO-ST Institute, aimed at reaching continuous superradiant operation through sequential atomic transport. It focuses on the preparation of cold atoms, the characterization of the atomic transport, and the development of the repumping scheme necessary to maintain population inversion. These efforts are done in parallel with the development of a theoretical description based on a Lindblad master equation and numerical calculations realized in collaboration with the UTINAM Institute to model the atom-cavity dynamics.

The numerical results describe the behavior of the system and predict key parameters such as the expected linewidth and output power. Such developments constitute a fundamental step for the realization of the continuous superradiant laser project and the basis for a full theoretical description.

time and frequency metrology, superradiance, cold atoms.

Full document (EN) : TEL-05603280