光纤通信fiber fabrication and cabling.pdf

Chapter 7 Fiber fabrication and Cabling 7.1 The basic concepts of optical fiber fabrication 7.2 Optical fiber cabling Two major stage: Two major stage: 1. Producing a preform (预型体, 光棒) 1. Producing a preform (预型体, 光棒) producing glass rod through reactions producing glass rod through reactions (using high pure SiCl , GeCl and POCL (using high pure SiCl , GeCl and POCL 4 4 3 4 4 3 with SiO by vapor-phase oxidation with SiO2 by vapor-phase oxidation 2 technique (气相氧化技术) technique ( ) a cylinder of silica composition (10 ~ 20 a cylinder of silica composition (10 ~ 20 cm in diameter, 50 ~ 100 cm long) cm in diameter, 50 ~ 100 cm long) containing core surrounded by a cladding containing core surrounded by a cladding with a desire index with a desire index Heating source: + → + 2 SiCl O SiO Cl 4 2 2 2 oxyhydrogen flame, microwave + → + 2 GeCl O GeO Cl 4 2 2 2 Reactions: 4PO Cl 3 + 3 O 2 → 2 P 2 O 5 + 6 Cl 2 2. Drawing heating preform to melting and drawing to obtain desire outer diameter controlling fiber quality and diameter by suitable rate of drawing Fiber-drawing apparatus Double crucible method fiber drawing Outside vapor-phase deposition (OVD, 外部气相轴向沉积法) Outside vapor-phase deposition (OVD, 外部气相轴向沉积法) Developed by