6533b82cfe1ef96bd128fc2b

RESEARCH PRODUCT

Mid-infrared supercontinuum generation in chalcogenide and telluride fibers for sensor devices

subject

description

This thesis reports on the progress made during my PhD concerning supercontinuum generation and its application in two types of materials: chalcogenide and tellurite glasses. Concerning the chalcogenide axis, two new arsenic-free compositions are developed: Ge20Se60Te20 and Ge20Se70Te10. Thermal and optical properties of these two glasses are studied and two types of fibers are manufactured: a step-index fiber and a suspended core fiber. The generation of supercontinuum in these two fibres, pumped by an optical parametric amplifier, gives competitive results compared to the current state of the art of supercontinuum generation in chalcogenide fibres. Supercontinuums widening between 2 and 14 µm are obtained. Concerning the tellurite axis, the generatedsupercontinuums confirm the previous results obtained with this type of fiber. The impact of pumping types is then studied with respect to the coherence of the supercontinuum in different fibre dispersion regimes when the pumping is of low power. Supercontinuum generation is also made with a new compact femtosecond laser source. Indeed, supercontinuums previously generated by an optical parametric oscillator can now be obtained by pumping the fiber with new compact femtosecond laser sources recently developed around 2 µm and commercially available. The supercontinuums obtained during my PhD thesis are used in various supercontinuum absorption spectroscopy experiments, in particular between 2 and 4 µm for methane detection.