GI-POF Prepared by the Dopant Diffusion Co-extrusion Process
Atsushi Kondo, Makoto Asai, Ryoma Hirose, Takaaki Ishigure and Yasuhiro Koike
We have proposed the dopant-diffusion co-extrusion process for fabricating a graded-index polymer optical fiber (GI-POF). This process enabled to fabricate GI-POFs continuously, which dramatically improves the process cost of fabricating the GI-POFs, compared to the conventional preform method. According to the Fick’s first law of diffusion, the refractive index distribution of the prepared GI-POF was initially expected to have a tail part at the core-cladding boundary. However, it was revealed that the GI-POF did not actually have this type of profile. Furthermore, it was confirmed that the refractive index profiles were controlled to the optimized index profile by changing the temperature of the diffusion zone.