In 1980s, the first generation called wideband WDM (wavelength division multiplexing) using two widely spaced wavelengths in the 1310nm and 1550nm appeared. In early 1990s, the second generation narrowband WDM with two to eight channels was used. But people would never be satisfied with network transmission rate. They want to see videos or watch movies which require a large amount of bandwidth capacity. Because of these consumers’ demands for bandwidth, by the mid-1990s, DWDM (dense wavelength division multiplexing), the new generation of optical fiber communication technology emerged. DWDM is a technology that puts data from different sources together on a single optical fiber, with each signal carried simultaneously on its own separate light wavelength. Advantages

After DWDM came into the world, it lays the foundation for the traditional electronic networking developing into optical networking. It makes optical fiber fully applied and brings many adv ... Read more »