Infrared optical properties of polycrystalline silver halide fibers

The power transmission characteristics at 10.6 μm, and the infrared spectral transmission from 2 to 13 μm, of extruded silver halide fibers of composition AgCl_0.95Br_0.05 have been investigated. The transmitted power at 10.6 μm remains linearly dependent on the input power up to at least 40 W, with a total loss coefficient of about 0.7 dB/m. The output power has a Gaussian shape with an angular width of 60° independent of the input power geometry in a fiber of about 2 m length. The spectral transmission shows a number of sharp absorption features attributed to water and CO⁻²₃ impurities, superimposed on a background loss that can be fit to an expression of the form (16.2λ⁻²+0.5) dB/m, with λ in μm. This background is a consequence of the scattering mechanism in these fibers.