Wavelength division multiplexing WDM, CWDM and DWDM applications

The fiber optics has become the most preferred media for this very large data traffic. TDM (Time Division Multiplexing) has been the most practical method to divide the significant capacity of a single fiber optics into several communication channels. This technology is still limited by the large complexity of high-flow modulation and multiplexing equipment. Presently. a complementary approach proves its potential: Wavelength-Division Multiplexing (WDM). The evolution of WDM allows now a very small spacing between channels wavelength, in run, generating DWDM (Dense Wavelength Division Multiplexing). The networks with individual fibers including more than 100 independent optic channels, as well as those with bidirectional flow are already available on the market. CWDM (Coarse Wavelength Division Multiplexing) represents an economical application of a mature technology which may provide options where the capacity of fibers is limited.