Single Crystal Tellurium Semiconductor Core Optical Fibers

Tellurium (Te) semiconductor core optical fibers with silicate glass cladding were drawn by the molten core method. The as-drawn precursor fiber has a large core diameter of about 123 µm, which was found to be polycrystalline. What is more, a Bridgman-type fiber postprocessing technique was constructed and used for the first time to anneal the polycrystalline Te semiconductor core optical fibers. The Te core in precursor fiber was melted and recrystallized to single crystal Te with c-axis orientation parallel to fiber axis, which was confirmed by X-ray diffraction, single crystal X-ray diffraction, micro-Raman spectra, and transmission electron microscope measurement results. Enhanced conductivities were observed in single crystal Te semiconductor core optical fibers under illuminated and stress states, respectively. This work demonstrates that the Bridgman-type fiber postprocessing technique could be an effective way to fabricate single crystal semiconductor core optical fibers with large core diameters (∼ 100 µm) and long lengths (a few centimeters).