Flexible ordered bundles of infrared transmitting silver-halide fibers: design, fabrication, and optical measurements

Ordered bundles of silver-halide fibers, which are highly transparent in the middle infrared, are fabricated by multiple extrusions from single crystals. We fabricate and characterize the optical properties of thin and flexible bundles of diameters of 0.7-2.0 mm that incorporate 100 individual fibers. The measurements include attenuation, resolution, cross talk, near-field scanning of single fibers in the bundle, and bending losses. Bundles of lengths of several meters transmit thermal images of bodies whose temperature is near room temperature. These bundles would be useful for medical, industrial, and military applications, and in particular for endoscopic thermal imaging.