Fabrication and characterization of Ge–Sb–Se–I glasses and fibers

Abstract

Chalcogenide glasses of the Ge₂₀Sb₅Se_75−x I _x (x = 0, 5, 10, 15, 20 at.%) system were prepared. This study was performed to examine some Ge–Sb–Se–I glass physical and optical properties, the structural evolution of the glass network, and the optical properties of the infrared glass fibers based on our previous studies. The variation process of the glass physical properties, such as transition temperature, glass density, and refractive index, was investigated from the glass of Ge₂₀Sb₅Se₇₅ to the Ge₂₀Sb₅Se_75−x I _x glass series. The structural evolutions of these glasses were examined by Raman spectroscopy. The Ge₂₀Sb₅Se₅₅I₂₀ composition was selected for the preparation of the IR fiber. The Ge₂₀Sb₅Se₅₅I₂₀ glass was purified through distillation, and the intensity of the impurity absorption peaks caused by Ge–O, H₂O, and Se–H was reduced or eliminated in the purified glasses. Then, Ge₂₀Sb₅Se₅₅I₂₀ chalcogenide glass fiber for mid-infrared transmission was fabricated using high-purity materials. The transmission loss of the Ge₂₀Sb₅Se₅₅I₂₀ fiber was greatly reduced compared with that of the Ge₂₀Sb₅Se₇₅ glass fiber. The lowest losses obtained were 3.5 dB/m at 3.3 μm for Ge₂₀Sb₅Se₇₅I₂₀ fiber, which was remarkably improved compared with 48 dB/m of the unpurified Ge₂₀Sb₅Se₇₅ fiber.