Tunable UDWDM Transmitter With Optical Comb Source
In fiber optical communications, high capacity transmission is one of the main challenges. Wavelength Division Multiplexing (WDM) is a key technology for effective utilization of fiber bandwidth and it is used in the realization of all optical multi-access networks. Two approaches are observed in the development of WDM systems: one presents the concept of the highest channel bit rate, the other, preferred for a subscriber loop, focuses on a relatively low channel transmission rate and a small wavelength separation. The number of channels and channel separation depends on the progress of the optical source technology and the lowest channel spacing implemented currently in systems is 25 GHz.