OPTICAL FIBER CORE MATERIAL AND ITS PRODUCTION

摘要

PURPOSE:To eliminate the need for secondary fabrication, etc. at the end face of a light exit face by maintaining a refractive index distribution to maximize the refractive index on the light exit face side in one end part of a core material in the axial line direction thereof. CONSTITUTION:The refractive index distribution to be maintained at tone end of the core material is formed by adjusting the mixing ratio of a core material polymer and a high refractive index component polymer. Any polymers such as polymethyl methacrylate and ethyl acrylate-2-hydroxyethyl acrylate copolymer which have transparency and desired refractive index are usable as the core material polymer. The polymers polymerized by polymn. methods such as soln. polymn. and mass polymn. method which yield the polymers having excellent transparency are more preferably used. The polymers formed by soln. polymn. in the presence of a mercapto compd. chain-transfer agent are more preferable in the case of copolymerizing monomers contg. a hydroxyl group or other crosslinkable groups.