Noriaki Taketani

Low excess losses in a Y-branching plastic optical waveguide formed through injection molding

We have demonstrated low excess losses (1.9 dB at 660-nm wavelength) in a Y-branching plastic optical waveguide (POWG) that was fabricated using an injection-molding method. The waveguide had an amorphous vinyl polymer as the core and transparent polyolefin as the cladding. We then studied a method for isolating the excess loss in the Y-branching POWG, and with that method we estimated the lower limit of the loss to be 1.41 dB at 660 nm. The sample had a heat-resistant plastic optical fiber (POF) with a core composed of crosslinked poly (methyl methacrylate) (PMMA) copolymer, and a cladding composed of poly (tetrafluoroethylene-co-hexafluoropropylene). The POWG has sufficient reliability for ordinary uses below 100 °C. A model for a bidirectional wavelength-division multiplexing opticalcommunication system with the developed Y-branching POWG and the POF was also demonstrated.

Multiplexed Optical Transmission System For Automobiles Using Polymer Fiber With High Heat Resistance

A multiplexed optical transmission system for automobiles utilizing newly developed polymer fiber has been proposed. The system is composed with a star-shaped optical network, in which the ootical signals can be transmitted bi-directionally through polymer optical fiber and optical branches with the central and local controllers. The polymer fiber has been developed for this purpose in order to overcome the conventional problems which prevented its wide use for a long time. The new polymer fiber is fabricated with a thereto-setting resin for core which is pushed out from heating furnace after the process of polymerization. The fiber shows the desirable characteristics for this application, that is, the heat resistance is as high as 200°C, and the transmission loss is as low as 0.5003/m at 660 nm wavelength.

A study on extrusion process for a crosslinking resin.

橋かけ性樹脂の押出成形法として, モノマーを細管内に移送させながら重合させ順次押出す手法について, 試料としてラジカル反応で重合速度の早いアクリル系モノマーを用いて検討した. その結果, 押出成形の可否は, 試料がチューブを通過する時の平均管内摩擦係数で整理できることを明らかにした. また, チューブの内径は約1mmが好ましく, これ以下では平均管内摩擦係数が小さくなるにもかかわらず, ポリマを吐出させる圧力が大きくなり表面形状が破壊された成形体が押出された. また, 1mm以上ではポリマー成形体の中央部に未反応部が残っており, 均一に重合したものを得ることが困難であった. この平均管内摩擦係数を, 滑剤を用いて低減することにより, 表面の平滑な成形体が得られることが判明した.