Ultrapurification of Raw Materials of Silver Halide Optical Fibers

The preparation of high purity raw materials is the foremost section in fabrication of high quality optical fibers. The materiaJ of silver halide was ultrapurified by horizontal zone melting purification in CI2 atmosphere. Measurement results show that infrared absorbance will decrease as wavenumber increases at 800~4000cm-1 after the ultrapurification, and the absorption coefficient of silver halide preform crystal by CO2 laser caJorimeter is less than 5×10-4cm-1 at 10.6μm. The absorption coefficient decreases two order of magnitude after ultrapurification. The optical fiber loss is 0.3~0.5 dB/m.