MULTICORED PLASTIC OPTICAL FIBER AND ITS PRODUCTION

PURPOSE:To obtain an optical transmission line free from leakage and mixing of light by constituting the same of an optical transmission line consisting of plural amorphous transparent polymers, and a polymer having the refractive index lower than the refractive index of said polymers and the glass transition temp. higher than a room temp. CONSTITUTION:Plural rods 1 each consisting of an amorphous transparent polymer are disposed at an optional interval in a polymer case and are fixed therein; thereafter, a monomer that polymerizes to a polymer having the refractive index lower than the refractive index of said polymer and having the glass transition temp. higher than a room temp. is filled therein and is polymerized to form a solid body 2. The preform formed into one body in such a way is elongated to produce a multicored optical fiber. Each optical transmission line in the monolithic solid body is thus free from leakage and mixing of light and since the connection of the plural optical transmission lines is easily and simultaneously accomplished by one time of connection, the need for any intricate mechanism and labor for working is eliminated.