Scattering characteristics of crystallites in fluoride optical fibers

This paper evaluates the scattering loss in ZrF(4)-based fluoride optical fibers that is caused by ZrF(4) and ZrO(2) crystallites. To determine this, efficiency factors of each of these crystals are calculated. We make clear that the presence of ZrO(2) crystals of the order of a submicron smaller than 0.2 microm in diameter effectively elevates the Rayleigh scattering factor as the particle number increases. Scattering loss characteristics in current fluoride fibers are also discussed. In addition, ZrO(2) microcrystals in fluoride fibers are identified for the first time using Raman microprobe analysis. It is concluded that ZrO(2) microcrystals cause serious extrinsic scattering loss in current ZrF(4)-based fluoride fibers.