从1975年第一个实用化光纤通信系统问世至今 ,光纤通信技术已经历了28个年头。这近30年的发展历程 ,是光纤通信高速发展的历程。从点到点的传输 ,到有很强生存性的SDH网络 ;从简单的硬件设备连接到可管理控制的系统和网络 ;从低速小容量到高速大容量等 ,目前单信道速率已经达到 From the first practical optical fiber communication system in 1975 to the present, optical fiber communication technology has gone through 28 years. This nearly 30 years of development, is the rapid development of optical fiber communication process. From point to point transmission, to a strong survivability SDH network; From simple hardware devices connected to manageable control systems and networks; From low-speed small capacity to high-speed high-capacity, the current single-channel speed has reached