Optical fiber
 A resin-made optical fiber is composed of a core of a polymer or copolymer obtained from a polymerizable monomer, which contains at least 1 wt. % of a crosslinkable monomer, and a cladding of a polymer of copolymer having a refractive index smaller than the core. The optical fiber is fabricated by filling a polymerizable monomer into a hollow fiber like cladding material, which is adapted to form a cladding and is made of a polymer or copolymer, and then placing the resultant composite material under polymerizing conditions to polymerize the polymerizable monomer. The latter step may preferably be carried out by causing the composite material to travel continuously in the direction of its length into a polymerization zone where conditions for the polymerization of the polymerizable monomer are satisfied, whereby the polymerizable monomer is successively polymerized to form a core having a refractive index greater than the cladding. 
Kureha Kagaku Kogyo Kabushiki Kaisha
Y G Y Y B B B Y Y G
Y10T G02B Y10T Y10T B29C B29C B29C Y10T Y10T G02B
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Teruo Naohiro
Sakagami Murayama