Preparation of optical fibers based on Ge–Sb–S glass system

Unclad optical fibers based on Ge–Sb–S glass systems were prepared by preform drawing. It was shown that optical losses in fibers depend on the content of limiting impurities in glass. The correlation between the level of optical losses in fibers and the content of gas-forming dissolved impurities and heterophase inclusions in glasses was established. The minimum optical losses were equal to 300 dB/km at 5.35 μm wavelength in fiber from Ge25Sb10.5S64.5 glass prepared using chemical-distillation melt purification.