A novel fabrication method of graded index polymer optical fibers (GI-POFs) called the "co-extrusion process" is
proposed and demonstrated for first time. This continuous fabrication process can reduce the fabrication cost of GI-POFs.
Dopant diffusion temperature, dopant diffusion time, and the molecular weight of PMMA were optimized. By this
optimization, desirable refractive index profile was achieved. Therefore, it is exhibited that the GI-POF obtained by the
co-extrusion process has as high bandwidth as the one prepared by the conventional interfacial-gel polymerization process.