6533b820fe1ef96bd127966f

RESEARCH PRODUCT

Study of new tellurite glasses in the TeO2-ZnO-La2O3 (TZL) system for the manufacturing of mid-infrared multimaterial optical fibers and specialty optical waveguides

subject

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This thesis work was carried out using tellurite glasses from the TeO2-ZnO-La2O3 (TZL) ternary diagram for optical fibers manufacturing. The choice to use this system is motivated by the ambition to improve the transmission of optical signals within oxide glasses for which absorption bands related to OH groups are present in the transparency window. A structural study is first carried out on these glasses by Raman spectroscopy in order to understand the influence of the composition on physicochemical properties (especially on optical and thermal properties) but also to estimate the ability of a vitreous matrix to reorganize when subjected to a thermal solicitation such as the preform-to-fiber drawing process. Then, although TZL are less sensitive to OH than other tellurite glasses, their purification has to be considered to extend fiber transmission up to 4.5 µm. The impact of fluorinated agents introduced for this purpose into the vitreous matrix is evaluated and the optical attenuation measured on fibers is improved in comparison to previous works. In addition, the good shaping ability of TZL glasses makes it possible to envisage several applications for those compositions. Among them, we describe in this work the manufacturing of waveguides for integrated optics by high-precision mechanical machining, the co-drawing of different materials into a single "hybrid" fiber combining several functionalities, as well as the fabrication of step-index multimode fibers with a rectangular cross-section used to perform animal cell imaging, thus opening the way to biomedical applications.