Dense Wavelength Division Multiplexing(DWDM) is used for carrying multiple optic waves into one single optic fiber. Compared with CWDM, the CWDM possesses a much more dense wavelength intervals which can support up to 80 channels at present. And each channel can carry the 2.5Gbps light signal. Therefore, DWDM maintains a more stable wavelength than CWDM and is available for long diatance optical transmission. But the biggest shortage of DWDM is the high cost of device price and energy consumption, it is not suitable for the use among ordinary people.