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自从70年代研制出第一根低损耗光纤以来,光纤通讯迅速崛起,目前西方发达国家已逐渐建成国内光纤长途干线网。一些跨洋电缆也在兴建与计划之中。波分复用技术和光放大器技术的应用使得光纤的传输速率与无中继距离大大提高,传输体制由过去的PDH向SDH转变,不仅使得以光纤为基础的数字传输网路传输速率更高,还使得网路更加灵活、安全、易于管理。以下将介绍这些方面的新进展情况。
Since the first low-loss optical fiber was developed in the 1970s, optical fiber communication has rapidly risen. At present, the developed western countries have gradually built up a national long-distance optical fiber network. Some transoceanic cables are also under construction and planned. The application of WDM technology and optical amplifier technology has greatly improved the transmission rate of optical fiber and the distance without relay. The transmission system has been transformed from the previous PDH to SDH, which not only makes the optical fiber-based digital transmission network have higher transmission rate, but also Make the network more flexible, safe and easy to manage. The new developments in these areas are described below.