Thermal imaging by ordered bundles of silver halide crystalline fibers

Flexible bundles consisting of 70–2000 silver halide optical fibers were fabricated by extrusion of crystalline preforms. Such devices transmit in the mid-IR spectral region (4–20 μm), and are suitable for delivering thermal images of near room-temperature objects. Small diameter (1–3 mm) image guides of this type can thus map the temperature distribution of areas difficult to access by conventional devices. The fabrication of these guides, their optical properties, and their imaging capability are discussed.