greatly increase the fiber information transmission capacity, this is the wave division multiplexing ( WDM ) is the basic train of thought. Based on the WDM in last few years the major

breakthrough on the technology and market is tremendous drive, wavelength division multiplexing system development is very rapid. The current global practical pavement WDM system has more than 3000, and the practical system for maximum capacity already amounted to 320Gbps ( 2 x 16 x 10Gbps ). Laboratory of the highest level have reached 2.6Tbps ( 13 * 20Gbps ). Is expected in the near future, the practical capacity of the system can achieve 1Tbps level.

( 3) to realize optical networking

The utility of WDM system despite the great transmission

capacity, but basically is based on point to point communication system, its flexibility and reliability are also not ideal. If in the light path can achieve a similar SDH in circuit of transplanting function and cross connect function words, will add a new layer of power. According to this one main train of thought, optical networking not only can achieve large capacity optical network, but also can satisfy the network nodes and the continuous