Fabrication of extruded fluoroindate optical fibers

Reduction of scattering loss in fluoroindate glass fibers

“…This fluoroindate glass composition is particularly promising for applications in the mid-infrared spectral region due to its high transmission and relatively low rate of crystallization compared to ZBLAN glass [9]. However, the presence of surface crystallization (e.g., white precipitates) and roughness on the preforms, which were major scattering centers, caused high fiber loss and low fiber strength in our previous work [9].…”

“…Volume defects (e.g., contaminations from platinum crucible, bubbles, un-dissolved particles and crystals [7]) are imperfections within the glass matrices that are principally formed during glass melting. Surface defects (e.g., surface contaminations, micro-cracks, scratches [8] and surface crystallization) originate from the contact of the glass surfaces with molds or extrusion dies during casting and extrusion [9] and from the reaction of the glass surface with moisture in the atmosphere during fiber fabrication or storage.…”

“…Compared to the casting method, the extrusion technique is a versatile method for the production of low-loss microstructured optical fibers with various shapes produced from different types of glasses [18][19][20]. It also has been demonstrated that the extrusion method is suitable for the preparation of bubble-free rods, which typically exhibit better surface finish and fewer bubbles than cast rods [9]. However, both casting and extrusion methods unavoidably introduce surface contaminations (i.e., metallic particles and graphite particles) and surface scratches (leading to high roughness) generated during contact with molds or dies.…”

“…In our previous study [9], the extrusion technique was demonstrated to be a suitable method for the production of low loss fluoroindate fibers made from 32InF 3 -20ZnF 2 -20SrF 2 -18BaF 2 -8GaF 3 -2CaF 2 (IZSBGC) glass. This fluoroindate glass composition is particularly promising for applications in the mid-infrared spectral region due to its high transmission and relatively low rate of crystallization compared to ZBLAN glass [9].…”

“…This fluoroindate glass composition is particularly promising for applications in the mid-infrared spectral region due to its high transmission and relatively low rate of crystallization compared to ZBLAN glass [9]. However, the presence of surface crystallization (e.g., white precipitates) and roughness on the preforms, which were major scattering centers, caused high fiber loss and low fiber strength in our previous work [9]. The aim of this study is therefore to reduce the fiber scattering loss and to improve mechanical strength of unstructured fibers by minimizing surface crystallization and roughness through optimization of fluorination processes, extrusion and fiber drawing conditions.…”