[17p-P4-1~7] 3.14 光制御デバイス・光ファイバー

▲ [17p-P4-7] Low Tg Negative Graded Index Plastic Optical Fiber

〇Shunta Ueki¹ (1.Keio Univ.)

キーワード：plastic optical fiber, optical branching

Graded-index plastic optical fiber (GI POF) has attracted much attention as a short distance communication tool because of its flexibility and broadband properties. Optical branching is essential to form a GI POF network, however, current optical fiber couplers are costly and not reusable. In the previous studies, negative type GI POFs (N-GI POF) were considered to be useful because of their high broadband properties and optical branching abilities. N-GI POF has a refractive index profile where it is lowest at the central axis and highest at the core-cladding boundary, thereby, optical rays can easily be branched simply via contact between N-GI POFs, thus making optical fiber couplers unnecessary. It was suggested previously that optical rays could be branched effectively if the N-GI POFs contact spirally. Consequently, we decided to focus on fabricating low Tg N-GI POFs that can potentially be used for optical branching. It is important to note that low Tg N-GI POFs can be fabricated at a much lower temperature than the high Tg POFs. They are flexible and can be either bent or twisted together. The aim of our research was to fabricate a negative type GI POFs with a lower glass transition temperature and then to evaluate its optical branching abilities.