Optical fibers based on As–S–Se glass system

The core-clad optical fibers with polymer coating based on As-S-Se glass have been manufactured with the aim of measuring their optical and strength parameters for potential use in the middle infrared. The glass compositions, As 40 S 30 Se 30 and As 40 S 33 Se 27 , were chosen as a core and a clad, respectively. To prepare sulfoselenide glasses and fibers we used two main variants, i.e., the direct melting of initial elements and using arsenic monosulfide as an arsenic-containing component. The core-clad-optical fibers were drawn by the double-crucible method with the ratio of core/ cladding diameters (in μm) 300/400, 200/400 and 100/400. The minimum loss measured by the two-point method was equal to 0.7 dB m 1 at 5.5 μm. It is the best result on As-S-Se core-clad fibers with comparable content of sulfur and selenium. The numerical aperture (NA), found as the sine of half of the angle of the power spatial distribution in the far zone, has also been measured in 2 fibers and is 0.35 and 0.2. The average mechanical bending strength was equal to 0.8 GPa.