High‐thermally stable and high‐bandwidth graded index plastic optical fiber for vehicle networks

Abstract

Radial refractive index profiles within the graded index plastic optical fiber (GI-POF) is formed by adding a dopant to a polymer. This addition of the dopant significantly decreased the T g of the polymer due to the plasticization. This disadvantage made the installation of the GI-POF difficult, especially in vehicle networks in which high thermal stability is required. We have suggested 9-bromophenanthrene (BPT) as a novel dopant induced less plasticization for poly(methyl methacrylate) (PMMA) than the conventional dopants. However, although the fabricated GI-POF using BPT had high enough thermal stability for vehicle networks, the attenuation was 800 dB/km and it could not be used. This high attenuation was caused by contaminant in the fabrication process of fibers. In this study, we succeeded to fabricate a GI-POF with low-attenua-tion and high-thermal stability using highly pure BPT. Its attenuation was improved to 240 dB/km at 650 nm, which was enough transparency for vehicle networks. The T g of the GIPOF was improved to 107 C from 90 C. The thermal stability of the GI-POF below 85 C/dry and 75 C/85%RH was demonstrated to be as high as that of the commercially available step index POF. The bandwidth of the GI-POF could be estimated over 4.0 GHz for the 50-m fiber. These results demonstrated that our GI-POF should qualify to be used in vehicle network.

Thermal and spectroscopic studies of polymer protective coatings used in optical fibers technology

“…Despite the great interest in active optical fibers, used for special purposes, still a lot of attention is paid to classical optical fibers. Currently, studies concentrate on searching for new materials from which protective coatings can be made and on optimizing the coatings curing conditions [10][11][12][13].…”