Method and apparatus for manufacturing a graded refractive index plastic optical-fiber

摘要

A plastic optical-fiber is provided having a desired length and a desired graded refractive index. To this end, a base polymer is mixed with a non-polymerizable compound having a higher refractive index to obtain a fiber material. This material is then transformed continuously into a fiber in a fiber-preparing unit. A plurality of diffusion tanks are each provided with a solution, each solution having a level of viscosity different from one another. The fiber is then dipped successively into the solutions in the order from a lowest viscosity level to a higher viscosity level. During this process, the non-polymerizable compound and polymerizable compound diffuse inside the fiber and form a graded refractive index distribution. The polymerizable compound is then polymerized and hardened in a drying-and-heating unit. The fiber thus obtained is drawn and coated with a cladding.