CWDM and DWDM

 



WDM : Wavelength division multiplexing is a technology that simultaneously transmits two or more optical 
signals of different wavelengths in the same optical fiber.

CWDM : Coarse wavelength division multiplexing, generally covering wavelengths of 1270~1610nm , DFB lasers will be used , the channel spacing is relatively wide, usually 20nm , the main application, a total of 18 waves, relatively low cost, mainly used in Aggregation layer and access layer. So it can be used for our fronthaul, CWDM6 application.

DWDM : dense wavelength division multiplexing, the wavelength interval will be relatively small, 0.2nm~1.2nm . The main working wavelengths are 1525nm~1565nm in C -band and 1570nm~1610nm in L- band . It focuses on long-distance transmission and is applied to the transmission network. Therefore, the low-loss C -band is selected, and EML lasers are usually used. To ensure the wavelength, they are all equipped with TEC , so the cost of the device will be relatively high.

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