Infrared fibers manufacture from single crystals of the AgBr – AgI system

The article is devoted to the manufacture of infrared polycrystalline optical fibers based on crystals of the AgBr–AgI system. The synthesis of a charge with a purity of up to 99.9999 wt % was performed. Single crystals of the AgBr0.96I0.04, AgBr0.92I0.08, AgBr0.87I0.13 compositions were grown. By means of computer simulation, the extrusion parameters of unjacketed optical fibers based on crystals were selected, namely, the temperature was 180 °C, the speed of the plunger movement was 0.2–0.3 mm/min. Using the selected parameters, from the crystals by the extrusion method, fibers with a diameter of 525 μm and a length of 0.55–2.2 m were manufactured, and their optical transmission was measured. The fiber transmission spectra have covered the range from 3 to 25 μm. Optical losses were estimated using the cut-off method. They amounted to 0.3 ± 0.1 dB/m in the region from 10 to 14 μm. The fiber resistance to ionizing β-radiation has been investigated. The transmission parameters were retained when the fibers had been irradiated with doses up to 400 kGy.