Silver chloride and silver bromide materials of pure and mixed compostions were extruded into 1 mm fibers for use in propagating 10.6 μm laser radiation. Insertion loss and scattered light flux was measured incrementally along the fiber length. Absorption losses were estimated from the difference between extrapolated input power and the integrated scattered power; these were not significant at the relatively low power levels employed (<50mW). Fibers having insertion losses less than 4db/m exhibited a relatively constant amount of scattered light flux with the distance from the launching face and a scattered attenuation coefficient which increases linearly with this distance. Major losses were attributed to internal defects and strain within the fibers. The surface roughness - a function of the material hardness - was found to be a minor source of scattering losses. Fibers measuring insertion losses greater than 8-10 db/m always exhibited a scattered flux which falls off exponentially with distance for the launching face and a constant scattered attenuation coefficient. Internal strain appears greater in these cases.
L. H. Strong,
J. I. Masters,
"Optical and Material Properties of Extruded Silver Halide Fibers", Proc. SPIE 0618, Infrared Optical Materials and Fibers IV, (12 May 1986); doi: 10.1117/12.961096; https://doi.org/10.1117/12.961096