en fr Chalcogenide glass microstructured optical fibers for chemical sensing and wavelength conversion Fibres optiques microstructurées en verre de chalcogénure pour la détection despèces chimiques et la conversion de longueuReport as inadecuate




en fr Chalcogenide glass microstructured optical fibers for chemical sensing and wavelength conversion Fibres optiques microstructurées en verre de chalcogénure pour la détection despèces chimiques et la conversion de longueu - Download this document for free, or read online. Document in PDF available to download.

1 ISCR - Institut des Sciences Chimiques de Rennes

Abstract : The present works concern the elaboration of chalcogenide glass Microstructured Optical Fibers MOFs. Chalcogenide glasses present a large transparency window in the infrared and high non-linear optical properties. MOFs are based on only one glass, the guidance of the light beam in the fiber core is possible thanks to the presence of a periodic holes arrangement defining the microstructure. This particular mode guidance combined with the original properties of chalcogenide glasses leads to numerous potential applications. In this thesis different applications have been investigated. Indeed, the works focus on three main aims: power transmission in the II and III atmospheric transparency windows, the fabrication of a sensor for chemical species and wavelength conversion thanks to non-linear effects. Whatever the application, it is needed to synthesize very high purity glasses in order to reach optical losses as low as possible. Thus, the glass compositions selected to carry out the fibers As38Se62, As40S60, Te20As30Se50 and Ge10As22Se68 have been the subject of extensive researches to find the most appropriated purification processes. Thanks to the optimization of the purification methods, the elaborated fibers present optical losses as low as 1dB-m over a wide range of wavelengths. Such a result allows the transport of light power in the II or the III band depending on the glass composition. Regarding the development of a sensor in the infrared, a new fiber geometry has been performed. It consists in a fiber whose core is partially exposed to the external environment thanks to the presence of a slit along the fiber. Such a configuration was obtained by modifying the preform molding method. The detection tests carried out are promising. Indeed, the exposed core fiber is more sensitive than a single index fiber having a twice smaller external diameter. A small core diameter is needed to enhance non-linear effects. Thus, to generate such effects, two different fiber designs have been chosen: suspended-core multi-mode fibers Øc



Author: Perrine Toupin -

Source: https://hal.archives-ouvertes.fr/



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