Presentations

Additional design by controlling the radial graded-index a lens medium has generated considerable interest especially in reducing spherical abberation or increasing optical power. However, in the case of glass materials, it is difficult to prepare large dimensional GRIN materials with about 10 mm diameters. On the other hand, polymer materials are suitable for obtaining a large dimension such as 10mm-100mm. In this paper, we focus on the eye contact GRIN lens in which two concept are proposed: One is for a high power contact lens with low spherical aberration, and the other is for remedy of presbyopia.

ポリマー光ファイバーについて最も重要な光学特性である伝送損失と伝送帯域に着目して最近の開発状況を紹介した。

屈折率分布を持たせることにより現在、そして将来さらに必要とされる伝送容量を充分にカバーできる低損失広帯域ＧＩ型ＰＯＦの現状について紹介した。

Silica-based Single Mode (SM) Optical fiber has been extensively studied and used for long haul communication because of its high transparency and high bandwodth. However, since the core diameter of the SM fiber is only 5-10µm, the sliught amount of displacement in fiber connection causes a large coupling loss, which will dramatically increase the total costs in the FTTH and Interconnection. A Polymer Optical Fibers (POFs) with a large core diameter (0.5-1.0mm) is one of promising candidates to solve this problem. However, all commercially available POFs have been of the step-index (SI) type, so the bandwidth is only about 5MHz・km. Very recently haig- bandwidth graded-Index (GI) POF with a 0.5-1.0mm daiameter has been successfully prepared at Keio University for the first time.

In general, the dimension of the inorganic GRIN (Graded Index) materials is limited to several millimeter because of difficulty of the diffusion process. On the other hand, the advantage of the polymer GRIN materals is the ease in obtaining the large dimennsional GRIN region with a short reaction time. Several technique for obtaining such polymer GRIN materials and devices have been proposed. In this paper, we focus on the polymer GRIN contact lens for remedy of presbiopia, very large dimensional radial GRIN, and very high-bandwidth (2GHz・km) GRIN optical fiber and fiber-lens.

高密度通信が可能なＰＯＦとして、ＧＩ型ＰＯＦの開発に取り組み、これまでにＳＩ型ＰＯＦの400倍の伝送帯域、2GHz・kmを有するＧＩ型ＰＯＦの作製に成功し、その作製方法を提案してきた。今講演ではＧＩ型ＰＯＦの光学特性、および実際に作製したＧＩ型ＰＯＦの性能及び作製方法について紹介した。

We propose a new concept, Highly Scattered Optical Transmission Polymer (HSOT Polymer) as a new light source medium in which the light is effectively scattered and illuminated from the surface during light transmission. Since the light scattering is caused inside the HSOT Polymer due to specific heterogeneous structure, surrounding device such as diffuser film asnd dot printing etc. which is indispensable in conventional ones are not necessary in our proposal. The intensity of illumination is about 50% stronger than that of conventional PMMA plate systems.

高性能な光学材料の開発のために、厳密な評価および制御が必要な、光学特性に付き、簡便かつ高精度な測定法のいくつかを紹介した。

In genenral, the dimension of the inorganic Gradient-Index (GRIN) materials is limited to several millimeter because of difficulty of the diffusion process. On the other hand, the advantage of polymer GRIN materials is the eass in obtaining such olymer GRIN region with a short reaction time. Several technique for obtaining such polymer GRIN materials and devices have been proposed at Keio University. We focus on the first bifocalGRIN contact lens for remedy of presbyopia, very learge dimensional radial-GRIN (about 100nm diameter), and very high-bandwidth (2GhZ・km) GRIN optical fiber and fiber-lens.

屈折率分布型ポリマー光学材料として、二重焦点GRINコンタクトレンズ、大口径GRINレンズ（直径100mm）、低損失（90db/km at 572nm)・広帯域（2GHz/km)GI型ポリマー光ファイバーについて、その製法、光学特性について報告した。

HIgh-Bandwidth (2 GHz・km) GI POF and single-mode POF were successfully obtained by our interfacial -gel polymerization technique. The minimumu attenuation of transmission is 56 dB/km at a688nm wavelength.

A High-Bandwidth Graded-Index (GI) Polymer Optical Fiber (POF) was successfully obtained by our interfacial-gel polymerization technique. The bandwodth of GI POF is about 2 GHz・km that is four hundred times larger than that of commercially available step-nidex (SI) POF. The total attenuation of transmission is 60-150 dB/km.

プラスチック光ファイバーの伝送損失、伝送帯域、耐熱性、新しい機能性について、工業的に実用化されているもの、開発段階のものをも含め、概説した。光ＬＡＮ、データリンクなどの比較的短距離間の伝送では、分岐、接続箇所が多く、これらの領域を得意とするプラスチック光ファイバーの開発が大きく期待される。

High-Bandwidth Graded Index (GI) Polymer Optical Fiber and Single-Mode POF with good mechanical properties were successfully obtained by our inter-gel polymerization technique. The bandwidth of the GI-POF is about 1 GHz・km which is two hundred times larger than (5MHz・km) of the conventional step-index (SI) POF. The minimum attenuation of transmission is 56 dB/km at 688-nm wavelength and 94 dB/km at 780-nm wavelength. The single-mode POF, whose diameter was 3-15µm and the attenuation of transmission was 200dB/km at 625 nm wavelength was successfully obtained for the first time.

屈折率分布型ポリマー光ファイバーとシングルモード光ポリマーファイバーの作製方法を示し,屈折率分布型ポリマー光ファイバー中に色素を導入することにより、光増幅を確認した。

屈折率分布型光学材料の中でも特に実用化が望まれている遠近両用のコンタクトレンズの作製方法及びその光学特性と、現在光通信の分野で注目されてきた屈折率分布型ポリマー光ファイバーの伝送帯域特性について解説している。

ＧＩ型ＰＯＦ中に加えるドーパントの種類の最適化、及びファイバ延伸時の張力の最適化により70℃〜85℃の高温雰囲気下において伝送帯域特性、伝送損失特性がともに維持されるＧＩ型ＰＯＦの作成が可能になったことを詳細に報告した招待講演。

高分子であるプラスチック光ファイバー（POF）に傾斜機能を応用すると伝送速度が格段に速くなり光通信が家庭まで行き渡る。