Abstract: The silver halide fibers were made by means of hot extrusion. SEM micrographs show that the grain sizes of the fibers do not change when temperature of hot extrusion T=120~210℃ and grain size 1-2μm. The pressure is decreased as the temperature increases when T >210℃, The grain size is 5-10μm at 250℃. The growth of grains results in scattering loss increment. The temperature and pressure airs decreased when the model is smeared with lubricant, but the lubricant results in loss increment.

Key words: infrared optical fiber, silver halide, hot extrusion, microstructure