Moïse DEROH "Brillouin and Kerr interactions in specialty optical fibers for near and mid-infrared applications"

Moïse DEROH PhD Works "Brillouin and Kerr interactions in specialty optical fibers for near and mid-infrared applications"

Abstract : During the last decade, it is worth to mention the significant evolution of the spectral coverage of compact coherent laser sources towards the mid-infrared, in particular stimulated by spectroscopy and bio-photonic applications. The present thesis is part of this development through the investigation of specialty optical fibers designed to bridge the gap between the near-infrared and mid-infrared regions, especially for wavelengths around 2 μm. These fibers based on tellurite glasses or heavily germanium-doped silica fibers exhibit advantageous nonlinear characteristics for the development of laser systems or frequency conversion devices, by using the stimulated Brillouin scattering and Kerr effect. Our experimental measurements reveal a significant increase of Brillouin efficiency (up to 67 times higher) when compared to standard telecom silica fibers. We demonstrate the possibility of developing Brillouin fiber lasers with linewidths and thresholds about few tens of kilohertz and hundreds of mW, respectively. Such Brillouin laser cavities can also generate optical frequency combs by multiple four-wave mixing. The resulting spectral sources are shown to be symmetrical, stable and frequency-tunable. Finally, we show that the highly doped silica fibers have the distinctive feature of reduced sensitivity of the Brillouin shift to the mechanical tensile strain and temperature. In particular, the high 98 mol % doping level makes possible to obtain a temperature-insensitive elastic frequency at wavelengths of 1.55 and 2 μm. This athermal behavior is fundamental to discriminate the effects of temperature and mechanical strain in the field of fiber sensors.

Jury Composition : 

Hervé MAILLOTTE, Directeur de Recherche, Université Bourgogne - Franche-Comté, Phd  Co-Director

Thierry CHARTIER, Professeur des Universités, Institut FOTON (UMR5082) ENSSAT - Université de Rennes , Reporter

Sylvain GIRARD;Professeur des Universités, Laboratoire Hubert Curien, Université Jean Monnet de Saint-Etienne, Reporter

Alexandre KUDLINSKI,Professeur des Universités, Laboratoire PhLAM, IRCICA Campus CNRS Haute Borne? Université de Lille 1, Reviewer

Thibaut SYLVESTRE, Directeur de Recherche, Université Bourgogne - Franche-Comté, Phd Director

Bertrand KIBLER,  Chargé de Recherche, Université Bourgogne - Franche-Comté, Laboratoire ICB, Phd  Co-Director

Jean-Charles BEUGNOT, Chargé de Recherche, Université Bourgogne - Franche-Comté, Phd  Co-Director

Birgit STILLER, Chargé de Recherche, Max Planck Institute for the Science of Light, Reviewer

Localization : Amphithéâtre Jean-Jacques Gagnepain - Institut FEMTO-ST, 15B Avenue des Montboucons, 25030 Besançon Cedex