DEDEYAN Serge : O and E band amplification Based on Bismuth doped amplifying fibers: study of the active Bismuth center and optimization of the amplifier configuration

Résumé de thèse :

Since the first report of a near-infrared broadband luminescence in Bismuth-doped silica glass in 1999 and the demonstration of optical amplification and laser operation, results on Bismuth-doped fibers have been accumulating. In contrast to rare-earth -doped materials, the position of the emission and absorption bands in Bismuth-doped glasses strongly depends on the composition of the host matrix and on the excitation wavelength. This makes it easier to operate at different wavelengths and then create optical fiber amplifiers for low-loss windows of standard single-mode fibers, which are not covered by Erbium-doped optical amplifiers (limited to the 1530-1625 nm wavelength range). Therefore, Bismuth-doped fiber amplifiers (BiDFA) open the way to bandwidth increase in currently used optical fiber infrastructure and hence cope with the needed rise in capacity of future fiber networks. To date, the nature of the Bismuth active center (BAC) responsible for the amplification is unknown despite the large number of works on the subject. Various studies show that there are several active and inactive centers in competition whose proportions depend on the composition of the host glass, the preform manufacturing conditions (process, working atmosphere, temperature), or even the fiber drawing conditions. In this thesis, carried out within the framework of SIMBADE project, our work will focus on optimizing Bismuth-doped optical fibers drawn from preforms manufactured by the Modified Chemical Vapor Deposition (MCVD) technique. Optimizing the performance of a BiDFA is complex because the choice of the manufacturing parameters adapted to favor the desired BAC remains empirical. Our primary objective is to enhance the amplifying performances of these fibers in the O-band (1260-1360 nm) through systematic investigation of various parameters related to the fiber itself and also to the architecture of the amplifier. Subsequently, we will shift our focus to other bands such as E-band (1360-1460 nm). Furthermore, we aim to study the characteristics of BAC within Bismuth-doped fibers by deeply analyzing their optical and spectroscopic properties.

Doctorant : DEDEYAN Serge

Directeur de thèse : BIGOT Laurent, EL HAMZAOUI Hicham