Ordered bundles of infrared-transmitting AgClBr fibers: Optical characterization of individual fibers

Silver halide (AgCl_xBr_1-x) crystals were extruded to form polycrystalline fibers that are highly transparent in the spectral range 3-30 μm. Ordered bundles consisting of as many as 9000 fibers were fabricated by multiple extrusion steps. The transmission loss of an individual fiber in the 100-fiber bundles was 0.12 dB/cm, and the cross talk between neighboring fibers in the 900-fiber bundles was 25%. Thermal images of bodies at room temperature have been transmitted through the bundles. Such ordered bundles provide a solution for the problem of thermal imaging in regions where there is no line of sight between a thermal camera and a warm object.